Are primes brighter and sharper than wide open zooms

Post by Siddhartha Jain
Hi,
Given two lenses, one a prime (say 28mm) and the other a zoom (say
28-75mm) and both with an aperture of f2.8 -
- Will the prime be brighter than the zoom because it has fewer lens
elements?
- Will the prime be sharper wide open than the zoom at 28mm?
Ofcourse, a lot will depend on the particular makes and models being
compared but is there a rule of thumb?
- Siddhartha

In a word NO. At least it is no if you are talking about real life
situations.

However ---- In general primes will be sharper unless the zoom is a
much better quality lens. Of course that is possible and a really good zoom
can outperform a poor prime any day.

--
Joseph Meehan

Dia duit

Digital Photography Now

2005-09-28 15:15:42 UTC

A good prime should be sharper and exhibit fewer optical aberrations
compared to a zoom, with the aperture set wide open. Stopping the zoom down
should improve sharpness, but then you may lose the desirable effect of
limited depth of field, if that's what you wanted. Zooms typically have
different geometric distortion throughout the zoom range, usually barrell at
the wide end and pincushion at the tele end, being neutral somewhere in the
middle. A good prime should be able to combine better sharpness, contrast
and distortion characteristics compared to a zoom.

But there are some outstanding zooms out there these days and the advantage
of primes has been lessened as a result.

As the apertures are the same, there should be no difference in brightness.
The glass doesn't lose enough light in the way you fear to be a major
factor.

Ian

Digital Photography Now
http://dpnow.com
Visit our discussion forum at http://dpnow.com/Forums.html

d***@hotmail.com

2005-09-28 15:15:55 UTC

The prime may be slightly brighter than the zoom, something which may
be more important in the motion-picture industry
They use a term called the "t stop" of a lens and it is a measure of
the light loss through a lens.
<http://artsci-ccwin.concordia.ca/comm/lighting.htm>
The difference could be as little as a third or as great as (or greater
than) a 2 stop difference between what the f-stop is and the t-stop,
while the DoF will be the same and sharpnes is likely to be less with a
zoom than a prime.
In real life still photography I don't believe it would be noticable
(the difference in brightness), because of a variety of factors.
I personally would not lose any sleep over it.

Tony Polson

2005-09-28 20:49:34 UTC

Post by d***@hotmail.com
The prime may be slightly brighter than the zoom, something which may
be more important in the motion-picture industry
They use a term called the "t stop" of a lens and it is a measure of
the light loss through a lens.
<http://artsci-ccwin.concordia.ca/comm/lighting.htm>
The difference could be as little as a third or as great as (or greater
than) a 2 stop difference between what the f-stop is and the t-stop,
while the DoF will be the same and sharpnes is likely to be less with a
zoom than a prime.

I would very much like to hear which particular lenses for DSLRs or
35mm SLRs produce a 2 stop reduction in illumination from that
expected at any given aperture.

You needn't list all of them, merely give some examples. ;-)

Post by d***@hotmail.com
In real life still photography I don't believe it would be noticable
(the difference in brightness), because of a variety of factors.
I personally would not lose any sleep over it.

You wouldn't lose any sleep over a *two stop* reduction in
illumination? Either you are a very sound sleeper, or that reduction
simply doesn't exist. Or possibly both.

;-)

2005-09-28 23:21:26 UTC

"I would very much like to hear which particular lenses for DSLRs or
35mm SLRs produce a 2 stop reduction in illumination from that
expected at any given aperture."

2 stops is an awful lot, although I suppose some ancient zoom lenses
with lousy coatings might be that bad. One of the most complex zooms
I'm personally familiar with has about 40 elements, but nevertheless
suffers less than a 1-stop illumination reduction.

Brian

David Littlewood

2005-09-28 15:42:20 UTC

Other things being equal, yes to both, though with well-designed modern
lenses the difference may be small.

Brightness:

The conventional f-stop designation of aperture is a purely geometric
measure and takes no account of the actual transmission properties of
the lens. In reality, not all of the light going into a lens will come
out at the other end, and some of the light that does come out will be
scattered, and hence will reduce image quality.

Attenuation takes two forms: absorption and reflection/scattering.
Absorption is purely proportional to the depth of glass; a typical
figure for normal optical glass would be 10% for a total glass path
length of 100mm. Most photographic lenses would fall far short of this,
though some big lenses may get there. This attenuation is entirely
proportional to the length of the light path through glass; thus a zoom
with 12-15 elements is likely to experience more absorption than a fixed
focal length lens with 5-10 elements.

The other form is reflection from glass-air interfaces. This is
unavoidable, but can be reduced very greatly by coating. The percentage
of reflection depends on the refractive index of the glass, but for
typical n=1.50 optical glass (uncoated) the percentage is about 4%.
This, remember, is at each glass air interface, two per lens element.
Thus a compound lens with 15 elements will have 30 interfaces, and will
only transmit (0.96)^30 or about 20% of the light. (In fact another
20-40% will get to the film or sensor as scattered light - giving an
image of appallingly bad contrast). A single layer coating will reduce
the reflection to about 1-1.5%, and modern multi-coating reduces it to
around 0.3-0.5%.

This still gives a transmission factor of about 83.5% for a 20-surface
(10-element) system, against 91.4% for a 10-surface (5-element) system.

Resolution:

There is not the same direct relationship between complexity and
resolution as that above between complexity and transmission. However,
the compromises required to balance zoom ratio, overall size, mechanical
complexity and cost at the same time as controlling the seven distinct
varieties of lens aberrations mean that in almost every case the zoom
lens will have lower resolution than the fixed focal length lens of
similar quality of design and manufacture. You can see this from the MTF
function curves published by most lens manufacturers. Having just
checked some of these myself to answer your question, I am actually
quite impressed by how small these differences are; a couple of decades
ago the differences would have been much greater. (Be aware when
comparing MTF curves that they usually show wide open and f/8 data; as a
zoom will usually have a smaller maximum aperture than the comparable
fixed focal length lenses, you should avoid comparing these - best look
at the f/8 curves for a fair comparison.)

David

--
David Littlewood

Nostrobino

2005-09-28 15:57:22 UTC

Zoom lenses ARE prime lenses, notwithstanding the now-popular misusage of
"prime."

A prime lens is the camera lens as distinct from some other lens or
lenticular device (close-up lens, tele converter, etc.) used with it. It has
meant that since long before zoom lenses became commonplace, and therefore
no need to use another term to mean "non-zoom."

"Prime" is properly used in the sense of primary, main, chief or
original--all dictionary definitions for "prime."

There is NO dictionary definition for "prime" which means fixed focal length
or single focal length, or fixed or single anything else.

It would be nice if this nonsensical misusage, which obviously is based on
someone's misunderstanding of the term some years ago (and then spread like
cancer through the power of the Internet) could be stamped out. Surely "FFL"
is at least as easy to type as "prime" anyway, and there never was any
reason other than shortness to replace "fixed focal length" with the
incorrect term.

N.

Siddhartha Jain

2005-09-28 16:25:13 UTC

Post by Nostrobino
Zoom lenses ARE prime lenses, notwithstanding the now-popular misusage of
"prime."
A prime lens is the camera lens as distinct from some other lens or
lenticular device (close-up lens, tele converter, etc.) used with it. It has
meant that since long before zoom lenses became commonplace, and therefore
no need to use another term to mean "non-zoom."
"Prime" is properly used in the sense of primary, main, chief or
original--all dictionary definitions for "prime."
There is NO dictionary definition for "prime" which means fixed focal length
or single focal length, or fixed or single anything else.
It would be nice if this nonsensical misusage, which obviously is based on
someone's misunderstanding of the term some years ago (and then spread like
cancer through the power of the Internet) could be stamped out. Surely "FFL"
is at least as easy to type as "prime" anyway, and there never was any
reason other than shortness to replace "fixed focal length" with the
incorrect term.

I am aware of the mis-usage of the term *prime* and so guilty of
propogating the mis-usage but I feel its time the FFL camp realised
that there is no turning back.

- Siddhartha

Nostrobino

2005-09-28 17:35:29 UTC

Post by Siddhartha Jain

I am aware of the mis-usage of the term *prime* and so guilty of
propogating the mis-usage but I feel its time the FFL camp realised
that there is no turning back.

Well, not necessarily, though of course the more people who misuse the term,
the harder it will be to correct it.

Most people do not want to use wrong terminology since it makes them look
ignorant. In the case of "prime" being used to mean FFL, this has only
spread because readers who have not seen the term before, and then see it
used by people they assume are knowledgeable, naturally adopt it themselves.
Thus newbies are caught up in the misusage and (perhaps partly because they
feel using jargon will make them look knowledgeable too), contribute to the
spread.

Some will continue to use it anyway, but others will drop it (and some have
dropped it) when the error is pointed out to them.

N.

Eugene

2005-09-29 00:09:35 UTC

You make it sound like it's some kind of disease. In the grand scheme of
things, does it really matter? Languages are dynamic, and the meanings
of words are constantly changing. The original meaning of "prime" in the
photographic sense is just an invention anyway. Referring to the
dictionary I find no mention of lenses as related to the meaning of the
word "prime". Who is therefore to decide which usage is correct? You
apparently!

The first listing that I found at dictionary.com is...

"First in excellence, quality, or value"

I think therefore it's perfectly reasonable to refer to a high quality
FFL lens in this way.

Perhaps you should just "chill out" a little and stop preaching about
who or who isn't ignorant.

Post by Nostrobino
Well, not necessarily, though of course the more people who misuse the term,
the harder it will be to correct it.
Most people do not want to use wrong terminology since it makes them look
ignorant. In the case of "prime" being used to mean FFL, this has only
spread because readers who have not seen the term before, and then see it
used by people they assume are knowledgeable, naturally adopt it themselves.
Thus newbies are caught up in the misusage and (perhaps partly because they
feel using jargon will make them look knowledgeable too), contribute to the
spread.
Some will continue to use it anyway, but others will drop it (and some have
dropped it) when the error is pointed out to them.
N.

Brion K. Lienhart

2005-09-29 05:17:05 UTC

Post by Eugene
You make it sound like it's some kind of disease. In the grand scheme of
things, does it really matter? Languages are dynamic, and the meanings
of words are constantly changing. The original meaning of "prime" in the
photographic sense is just an invention anyway. Referring to the
dictionary I find no mention of lenses as related to the meaning of the
word "prime". Who is therefore to decide which usage is correct? You
apparently!

It's pretty much established jargon in the photo industry. I've seen it
used in this sense since the mid-70s (when I started paying attention to
photo stuff). I hardly think it can be blamed solely on the internet.

Eugene

2005-09-29 06:38:37 UTC

I don't think it has anything to do with the internet really. They've
been called prime lenses for as long as I can remember, and yes I do
pre-date the Internet ;-)

I certainly don't think it's some kind of fad. I suspect it would have
originated about the same time as zoom lenses. People needed a handy
term to distinguish their FFL lenses from the new zooms. FFL may be easy
and quick to write, but 'prime' is quicker to say. Also if we're going
to get pedantic about linguistics then why not take offence to the term
"zoom lens". Surely they should be called Variable Focal Length Lenses,
or VFL lenses. That's much better... Now we just have to re-educate all
the millions of poor ignorant fools using the incorrect terminology ;-)

Post by Brion K. Lienhart
It's pretty much established jargon in the photo industry. I've seen it
used in this sense since the mid-70s (when I started paying attention to
photo stuff). I hardly think it can be blamed solely on the internet.

Tony Polson

2005-09-29 08:21:23 UTC

Post by Eugene
I don't think it has anything to do with the internet really. They've
been called prime lenses for as long as I can remember, and yes I do
pre-date the Internet ;-)

If only it was as simple as referring to all fixed focal length lenses
as "prime" lenses. Most subscribers to this newsgroup probably aren't
old enough to recall that some manufacturers used the term "prime" to
refer to a high quality subset of their fixed focal length lenses.

What made a particular fixed focal length lens design a "prime" lens
was not clear. Why other fixed focal length lenses were not described
as "prime" lenses was even less clear. But what is clear is that
assuming all fixed focal length lenses were referred to as "prime"
lenses is wrong. It was marketing, pure and simple.

Since there is no accepted definition of a "prime" lens we should just
drop the term, as it serves only to confuse.

I like the idea of FFL and VFL, especially as so many VFL optics are
not true zooms because they do not hold focus when zoomed. They are
often termed vari-focal lenses (also "VFL"), which term could be
extended to include the true zooms.

FFL and VFL has my vote.

;-)

Eugene

2005-09-29 09:08:09 UTC

OK, I stand corrected. This does make sense. Actually now that I think
about it I don't tend to use the terms "prime" and "zoom" much anyway.
I'd nearly always just refer to the specific lens type. Like I'd just
say 50mm f1.4 rather than 50mm prime. Adding "prime" is kind of
redundant. If only one focal length lens is given then it's obvious I'm
not talking about variable focal length.

Also I think there would be very few situations where lumping everything
into 2 distinct groups would make sense. For example "zoom" could
equally refer to an EF-S 18-55, as it could to an EF 70-200 f2.8 L.
Aside from the fact that both lenses can change focal lengths, they
really have nothing much else in common. They serve entirely different
purposes and an entirely different market. Likewise "prime" (meaning
FFL) could equally refer to a 7mm circular fisheye, or a 1200mm
super-telephoto.

Grouping lenses by focal length ranges makes more sense, ultra-wide,
wide-angle, medium-telephoto, super-telephoto etc. FFL and VFL, while
correct and non-ambiguous are also I think too broad to be generally useful.

OK, well I wont use the term "prime" or "zoom" anymore as I can see that
they really don't add a lot of value.

Post by Tony Polson
If only it was as simple as referring to all fixed focal length lenses
as "prime" lenses. Most subscribers to this newsgroup probably aren't
old enough to recall that some manufacturers used the term "prime" to
refer to a high quality subset of their fixed focal length lenses.
What made a particular fixed focal length lens design a "prime" lens
was not clear. Why other fixed focal length lenses were not described
as "prime" lenses was even less clear. But what is clear is that
assuming all fixed focal length lenses were referred to as "prime"
lenses is wrong. It was marketing, pure and simple.
Since there is no accepted definition of a "prime" lens we should just
drop the term, as it serves only to confuse.
I like the idea of FFL and VFL, especially as so many VFL optics are
not true zooms because they do not hold focus when zoomed. They are
often termed vari-focal lenses (also "VFL"), which term could be
extended to include the true zooms.
FFL and VFL has my vote.
;-)

Nostrobino

2005-09-30 16:03:24 UTC

Post by Eugene
OK, I stand corrected. This does make sense. Actually now that I think
about it I don't tend to use the terms "prime" and "zoom" much anyway. I'd
nearly always just refer to the specific lens type. Like I'd just say 50mm
f1.4 rather than 50mm prime. Adding "prime" is kind of redundant. If only
one focal length lens is given then it's obvious I'm not talking about
variable focal length.

Exactly, and this is what makes my teeth hurt when I see someone mention
"28mm prime," for example. (As opposed to what, a 28mm zoom?)

Post by Eugene
Also I think there would be very few situations where lumping everything
into 2 distinct groups would make sense. For example "zoom" could equally
refer to an EF-S 18-55, as it could to an EF 70-200 f2.8 L. Aside from the
fact that both lenses can change focal lengths, they really have nothing
much else in common. They serve entirely different purposes and an
entirely different market. Likewise "prime" (meaning FFL) could equally
refer to a 7mm circular fisheye, or a 1200mm super-telephoto.
Grouping lenses by focal length ranges makes more sense, ultra-wide,
wide-angle, medium-telephoto, super-telephoto etc.

And in fact that is just how camera makers *do* group them, in my
experience. I have been for 25+ years mostly a Minolta man (until I got into
digital, anyway) and admittedly I'm less familiar with other manufacturers'
lens literature, but what I have seen has followed Minolta's practice of
grouping lenses as wide-angle, standard, telephoto, zoom, etc. I have never
seen any camera maker's literature use "prime" to mean FFL, and I sure hope
I never do. (It is almost unthinkable.)

N.

Chris Brown

2005-09-29 09:29:53 UTC

Post by Tony Polson
Since there is no accepted definition of a "prime" lens we should just
drop the term, as it serves only to confuse.

Feel free to go ahead. The rest of the world will carry on using it. You're
tilting at windmills.

Pete D

2005-09-30 03:43:20 UTC

Post by Tony Polson
Since there is no accepted definition of a "prime" lens we should just
drop the term, as it serves only to confuse.

Feel free to go ahead. The rest of the world will carry on using it. You're
tilting at windmills.

IAWCB, I vote to not care what they call non zooms and non fixed lenses! ;-)

Nostrobino

2005-09-30 16:13:37 UTC

Post by Tony Polson
Since there is no accepted definition of a "prime" lens we should just
drop the term, as it serves only to confuse.

Feel free to go ahead. The rest of the world will carry on using it.

"The rest of the world" is defined as the few dozen people who post in a
couple of newsgroups?

Camera manufacturers don't use "prime" to mean FFL. They never have. They're
not part of "the rest of the world," I guess?

Lens manufacturers do sometimes use "prime," and they use it to mean actual
prime lenses. Not FFL lenses, necessarily. Zeiss and Schneider, for example,
have catalogued variable prime lenses. Now can you guess what a variable
prime lens is? No? It's a prime lens of variable focal length. (Not a zoom,
because a true zoom has to be parfocal.)

I'll bet there are a lot more people (and a lot more knowledgeable) in Zeiss
and Schneider than there are in your "rest of the world" that thinks "prime"
means fixed focal length.

N.

no_name

2005-09-30 23:21:24 UTC

Post by Tony Polson
Since there is no accepted definition of a "prime" lens we should just
drop the term, as it serves only to confuse.

Feel free to go ahead. The rest of the world will carry on using it.

"The rest of the world" is defined as the few dozen people who post in a
couple of newsgroups?

Well, if you include some of the more common photo magazines. That's
where I got it from.

Nostrobino

2005-10-01 14:01:16 UTC

Post by Tony Polson
Since there is no accepted definition of a "prime" lens we should just
drop the term, as it serves only to confuse.

Feel free to go ahead. The rest of the world will carry on using it.

"The rest of the world" is defined as the few dozen people who post in a
couple of newsgroups?

Well, if you include some of the more common photo magazines. That's where
I got it from.

I'm genuinely sorry to hear that. As I mentioned recently in this thread,
Pop Photo has on two or three occasions misused "prime" in this way in their
captions, including at least once on a cover caption. As far as I know, they
have never called fixed focal length lenses "primes" in any of the articles
or columns themselves, so I presume those occurrences were the work of some
less punctilious caption writer.

N.

Paul J Gans

2005-09-30 04:44:00 UTC

Post by Eugene
I don't think it has anything to do with the internet really. They've
been called prime lenses for as long as I can remember, and yes I do
pre-date the Internet ;-)

If only it was as simple as referring to all fixed focal length lenses
as "prime" lenses. Most subscribers to this newsgroup probably aren't
old enough to recall that some manufacturers used the term "prime" to
refer to a high quality subset of their fixed focal length lenses.
What made a particular fixed focal length lens design a "prime" lens
was not clear. Why other fixed focal length lenses were not described
as "prime" lenses was even less clear. But what is clear is that
assuming all fixed focal length lenses were referred to as "prime"
lenses is wrong. It was marketing, pure and simple.
Since there is no accepted definition of a "prime" lens we should just
drop the term, as it serves only to confuse.
I like the idea of FFL and VFL, especially as so many VFL optics are
not true zooms because they do not hold focus when zoomed. They are
often termed vari-focal lenses (also "VFL"), which term could be
extended to include the true zooms.
FFL and VFL has my vote.
;-)

I dimly recall the term "prime lens" as being the
lens whose focal length was equal (at least roughly)
to the diagonal of the film frame. That made a 50mm
(or 45mm) lens "prime" for 35mm film.

A 135mm lens was then a "telephoto" and a 35mm lens
was a "wideangle".

Zoom hadn't been invented yet.

By the way I find acronyms very hard to remember (VHR).
I much prefer a pronoucible name. Most acronym
users seem to as well, since they often make the
acronym pronouncible.

---- Paul J. Gans

Peter

2005-09-30 04:57:02 UTC

The usual term for this is "normal lens"

Post by Paul J Gans
A 135mm lens was then a "telephoto" and a 35mm lens
was a "wideangle".

A telephoto lens, properly speaking, is one in which
the lens (when set to infinity focus) is closer to
the film/sensor than the focal length of the lens.

It is quite possible to have a wide angle lens
which is of telephoto constuction. Olympus compacts
have had such lenses for years. On an Olympus XA,
the point 35mm in front of the film is actually
just in front of the front element of the lens.

A lens which is significantly longer than a normal
is called a long-focus lens if it is not of telephoto
design.

Wide angle lenses for SLRs are generally of an
inverted telephoto type in which a point one
focal length in front of the film may be somewhat
behind the rear element of the lens.

Peter.

--
***@ktb.net

Tony Polson

2005-09-30 10:07:56 UTC

The usual term for this is "normal lens"

... or "standard lens", which is common usage in the UK.

Paul J Gans

2005-09-30 19:51:18 UTC

The usual term for this is "normal lens"

Post by Paul J Gans
A 135mm lens was then a "telephoto" and a 35mm lens
was a "wideangle".

A telephoto lens, properly speaking, is one in which
the lens (when set to infinity focus) is closer to
the film/sensor than the focal length of the lens.
It is quite possible to have a wide angle lens
which is of telephoto constuction. Olympus compacts
have had such lenses for years. On an Olympus XA,
the point 35mm in front of the film is actually
just in front of the front element of the lens.
A lens which is significantly longer than a normal
is called a long-focus lens if it is not of telephoto
design.
Wide angle lenses for SLRs are generally of an
inverted telephoto type in which a point one
focal length in front of the film may be somewhat
behind the rear element of the lens.

Yes. I know you are correct. But I don't think
that was the popular usage back then.

The general public was not very sophisticated
in such matters. Still isn't.

---- Paul J. Gans

Eugene

2005-09-30 05:26:33 UTC

Isn't that what's refered to as a "standard" lens?

Post by Paul J Gans
I dimly recall the term "prime lens" as being the
lens whose focal length was equal (at least roughly)
to the diagonal of the film frame. That made a 50mm
(or 45mm) lens "prime" for 35mm film.
A 135mm lens was then a "telephoto" and a 35mm lens
was a "wideangle".
Zoom hadn't been invented yet.
By the way I find acronyms very hard to remember (VHR).
I much prefer a pronoucible name. Most acronym
users seem to as well, since they often make the
acronym pronouncible.
---- Paul J. Gans

Paul J Gans

2005-09-30 19:52:13 UTC

Post by Eugene
Isn't that what's refered to as a "standard" lens?

Yes. That too.

---- Paul J. Gans

Post by Eugene

Nostrobino

2005-09-30 16:24:55 UTC

"Paul J Gans" <***@panix.com> wrote in message news:dhifqg$84p$***@reader1.panix.com...
[ . . . ]

I have never seen "prime" used in that way, but at least it's no more
incorrect than the way it's mostly being used in these newsgroups. ;-)

It used to be considered that the proper (or normal) focal length for a
camera was the diagonal of its negative. Similarly, the length + width of
the negative was considered a suitable focal length for portraits. I don't
think anyone has paid much attention to those rules of thumb since we've had
such a vast range of focal lengths available to us which were undreamt of a
few decades ago.

N.

Neil Ellwood

2005-09-30 16:41:06 UTC

In the UK in the sixties they were called normal lenses.

Post by Paul J Gans
A 135mm lens was then a "telephoto" and a 35mm lens
was a "wideangle".

The 135mm was often called a long focus lens (which most at that time
were), the 35mm were often retro-focus lenses but I cannot ever remember
them being called that.

Post by Paul J Gans
Zoom hadn't been invented yet.

Zooms were used on cine cameras quite a while before still.

--
Neil
Delete delete to reply by email

Nostrobino

2005-09-30 15:51:20 UTC

Post by Eugene
I don't think it has anything to do with the internet really. They've
been called prime lenses for as long as I can remember, and yes I do
pre-date the Internet ;-)

If only it was as simple as referring to all fixed focal length lenses
as "prime" lenses. Most subscribers to this newsgroup probably aren't
old enough to recall that some manufacturers used the term "prime" to
refer to a high quality subset of their fixed focal length lenses.
What made a particular fixed focal length lens design a "prime" lens
was not clear. Why other fixed focal length lenses were not described
as "prime" lenses was even less clear. But what is clear is that
assuming all fixed focal length lenses were referred to as "prime"
lenses is wrong. It was marketing, pure and simple.
Since there is no accepted definition of a "prime" lens we should just
drop the term, as it serves only to confuse.
I like the idea of FFL and VFL, especially as so many VFL optics are
not true zooms because they do not hold focus when zoomed. They are
often termed vari-focal lenses (also "VFL"), which term could be
extended to include the true zooms.

That is true. True zooms are essentially a subset of varifocals, I would
say.

Post by Tony Polson
FFL and VFL has my vote.
;-)

Mine too, but FFL first. To get rid of that pesky other thing. ;-)

N.

Nostrobino

2005-09-30 15:48:54 UTC

Much later than that, I think. I was fairly heavily into photography before
I saw my first zoom lens, the Voigtlander Zoomar. That was around 1960. I
bought my first zoom in the late 1960s, and I'm dead certain no one used
"prime" to mean FFL at that time or for many years after. FFL lenses were
still the common kind of lens to have, in any focal-length range, and so
there was no need for a special term to distinguish them. Zooms were just
not highly trusted. Throughout the 1970s and well into the 1980s, most of my
lenses were FFL. There simply wasn't any need to use a term for something
that was assumed anyway. It was the *zoom* that was the exception and needed
a special designation. Now it's the other way around.

People needed a handy term to distinguish their FFL lenses from the new
zooms. FFL may be easy and quick to write, but 'prime' is quicker to say.

So is "egg," and even quicker to write. If a term must be coined for FFL on
the basis of quickness and ease, I suggest "egg." It even has a vague
logical connection to the idea of single focal length, since the egg is sort
of a symbol for unity. But best of all, it has the overwhelming advantage of
not being incorrect. No one at present is using "egg lens" for anything
else, so the likelihood of confusion is practically nil.

Also if we're going to get pedantic about linguistics then why not take
offence to the term "zoom lens". Surely they should be called Variable
Focal Length Lenses, or VFL lenses. That's much better... Now we just have
to re-educate all the millions of poor ignorant fools using the incorrect
terminology ;-)

Well, you're partly right there, except that zoom lenses are not just
variable focal length lenses. A zoom lens, strictly speaking, is a variable
focal length lens that is parfocal (stays in focus throughout its
focal-length range).

Now it is certainly true that not all "zoom" lenses do this, and those that
don't are properly called varifocal lenses. For example, every "zoom" lens
I've ever seen on a projector has been a varifocal and not a true zoom. And
the "zoom" lenses on point-and-shoot cameras are for the most part really
varifocals.

So yes, sure, if you want to do that, then by all means let's get people
straightened out on that terminological inexactitude.

Right after we correct the "prime lens" snafu. First things first.

N.

Nostrobino

2005-09-30 15:21:12 UTC

Post by Brion K. Lienhart

Post by Eugene
You make it sound like it's some kind of disease. In the grand scheme of
things, does it really matter? Languages are dynamic, and the meanings of
words are constantly changing. The original meaning of "prime" in the
photographic sense is just an invention anyway. Referring to the
dictionary I find no mention of lenses as related to the meaning of the
word "prime". Who is therefore to decide which usage is correct? You
apparently!

It's pretty much established jargon in the photo industry. I've seen it
used in this sense since the mid-70s (when I started paying attention to
photo stuff).

I doubt that very much. I suspect that's a false memory, to which people are
very prone. I don't doubt that you saw "prime lens" used that long ago; I've
seen it used since the 1950s, when of course there was no need for a term to
distinguish FFL lenses from zooms. But I've been reading about photo stuff
extensively since I first got into it in 1951, and it wasn't until the early
1990s that I ever saw the term misused in this way. Obviously the misusage
started with someone's misunderstanding the term, and it's possible that you
did that long ago, though it seems somewhat unlikely.

People often "remember" things that never were. In another argument on this
same subject, a user claimed her father remembered using "prime lens" to
mean FFL lens back in the 1930s. Now why on earth would anyone use a term
meant to distinguish non-zoom lenses when there were no zooms?

Post by Brion K. Lienhart
I hardly think it can be blamed solely on the internet.

You're right there. I first saw it misused in this way on the old Fidonet,
some time before I had access to the Internet per se. That was back in my
386 days, so probably 1991 or so.

N.

Floyd Davidson

2005-09-30 19:40:33 UTC

Post by Brion K. Lienhart
I hardly think it can be blamed solely on the internet.

You're right there. I first saw it misused in this way on the old Fidonet,
some time before I had access to the Internet per se. That was back in my
386 days, so probably 1991 or so.

So, along with the correct meaning of words being fixed in time
by when you first understood them, the Internet didn't exist
until *you* discovered it too, eh?

Hmmmm...

--
FloydL. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska) ***@apaflo.com

Nostrobino

2005-09-30 21:31:40 UTC

Post by Brion K. Lienhart
I hardly think it can be blamed solely on the internet.

You're right there. I first saw it misused in this way on the old Fidonet,
some time before I had access to the Internet per se. That was back in my
386 days, so probably 1991 or so.

So, along with the correct meaning of words being fixed in time
by when you first understood them, the Internet didn't exist
until *you* discovered it too, eh?

I have no idea how you derive that from what I said. Perhaps you have your
monitor upside down.

N.

Nostrobino

2005-09-30 15:06:27 UTC

Post by Eugene
You make it sound like it's some kind of disease.

It is. And highly contagious, as we have seen.

Post by Eugene
In the grand scheme of things, does it really matter?

Yes. Words mean things. The meanings should not change willy-nilly, and
certainly not because some ignorant misusage becomes commonplace.

Post by Eugene
Languages are dynamic, and the meanings of words are constantly changing.

That argument has been used for as long as I can remember to justify
misusages of language.

Post by Eugene
The original meaning of "prime" in the photographic sense is just an
invention anyway.

No, it is not. "Prime" is used in the sense of "primary," "main," "chief,"
"original," etc. All are dictionary definitions (though not every dictionary
carries every one of those) and plainly that is the way the word was and is
properly used.

Post by Eugene
Referring to the dictionary I find no mention of lenses as related to the
meaning of the word "prime".

Look under "blue" and you'll probably find no mention of shirts, either. Do
you take that to mean that "blue shirt" can be taken to mean a red shirt, or
any other meaning unrelated to the usual meaning of "blue"?

What do the terms "primary lens," "chief lens," or "original lens" have for
you? Fixed focal length? I don't think so.

There is NO dictionary definition for "prime" that means fixed focal length
or fixed anything else.

Post by Eugene
Who is therefore to decide which usage is correct? You apparently!

That "decision" was made before I got involved in photography, which was
over 50 years ago. Since zoom lenses then were unheard of for 35mm cameras
(at least I don't recall any then), obviously there was no need for a term
to distinguish non-zooms from zooms.

Post by Eugene
The first listing that I found at dictionary.com is...
"First in excellence, quality, or value"
I think therefore it's perfectly reasonable to refer to a high quality FFL
lens in this way.

That is one of several meanings for "prime," but it isn't how the term is
being misused. If it were, that would at least reduce the objection to it,
but would still leave a good deal of confusion. Who is to decide (as you put
it) which lenses are "high quality" and which are not? You?

Post by Eugene
Perhaps you should just "chill out" a little and stop preaching about who
or who isn't ignorant.

I've been saying the misusage is ignorant. It is. I haven't said that the
people misusing the term are ignorant. On the contrary, I presume that most
of them are folks of at least ordinary intelligence who have innocently
picked the misusage up from Usenet and elsewhere. To be ignorant of some
particular state of affairs before one has the facts is hardly a shameful
thing. To try to DEFEND that ignorance after being apprised of the facts,
however, is stupid. Please note that I am making a careful distinction
between ignorance and stupidity. The former is often only temporary; the
latter tends to be lasting.

N.

Floyd Davidson

2005-09-30 19:37:12 UTC

Post by Nostrobino
I've been saying the misusage is ignorant. It is. I haven't said that the
people misusing the term are ignorant. On the contrary, I presume that most
of them are folks of at least ordinary intelligence who have innocently
picked the misusage up from Usenet and elsewhere. To be ignorant of some
particular state of affairs before one has the facts is hardly a shameful
thing. To try to DEFEND that ignorance after being apprised of the facts,
however, is stupid. Please note that I am making a careful distinction
between ignorance and stupidity. The former is often only temporary; the
latter tends to be lasting.

Your entire diatribe about language and word usage is then,
according to the above, *stupid*.

Language *is* dynamic. Dictionaries are *not* an authoritative
source of *correct* word usage, and this abjectly silly
suggestion that any jargon not found in a dictionary is
therefore wrong is a demonstration that you are ignorant about
this topic. Dictionaries are a compilation of current usage,
and have very little to do with what is or is not "correct".

Whether it is jargon, which might well be restricted to a small
enough fraction of all speakers and therefore will never show up
in any general dictionary, is unimportant. All that counts is
whether the speaker does in fact convey the desired meaning to
the target audience.

The essence of all that has previously been explained in detail
by others, and continued efforts to "DEFEND that ignorance" is,
in your own words: stupid.

--
FloydL. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska) ***@apaflo.com

Nostrobino

2005-09-30 21:49:54 UTC

Your entire diatribe about language and word usage is then,
according to the above, *stupid*.
Language *is* dynamic.

Again, that is the eternal argument of the semi-literate and those whose
grasp of language is feeble. Every error is followed by the excuse,
"language is dynamic." Since these people cannot be made to understand their
mistakes, they never improve.

Post by Floyd Davidson
Dictionaries are *not* an authoritative
source of *correct* word usage, and this abjectly silly
suggestion that any jargon not found in a dictionary is
therefore wrong is a demonstration that you are ignorant about
this topic. Dictionaries are a compilation of current usage,
and have very little to do with what is or is not "correct".

Try to organize your argument such that it supports one side or the other.
If dictionaries "are a compilation of current usage," and "language *is*
dynamic," then dictionaries must reflect that dynamism according to your own
assertion and can hardly be "*not* an authoritative source of *correct* word
usage" as you claim in the same paragraph.

Make up your mind which side of the argument you're taking. You cannot take
both sides simultaneously, unless you're John Kerry.

N.

Floyd Davidson

2005-10-01 01:45:11 UTC

Your entire diatribe about language and word usage is then,
according to the above, *stupid*.
Language *is* dynamic.

Hogwash. You are suggesting we should all be speaking Chaucer's
English. Patently, and we would hope obviously to anyone with
half a thimble full, *stooopid*. And I don't mean ignorant, I
mean stupid.

You have real difficulty with understanding English, don't you?

Dictionaries are a *history* of past usage that has become
common enough to be recorded as such. But you cannot 1) find a
current dictionary that includes correct usage *as* *it*
*exists* *today*, or 2) find one that predicts what will be
correct tomorrow, or 3) find one that lists the jargon for all
fields. Which says, simply put, that a dictionary is *not*
the authority on "correct" word usage.

Post by Nostrobino
Make up your mind which side of the argument you're taking. You cannot take
both sides simultaneously, unless you're John Kerry.

Learn to read the English language. You'll do a *lot* better
yourself.

--
FloydL. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska) ***@apaflo.com

Jeff R

2005-10-01 02:28:11 UTC

Post by Floyd Davidson
Hogwash. You are suggesting we should all be speaking Chaucer's
English. Patently, and we would hope obviously to anyone with
half a thimble full, *stooopid*. And I don't mean ignorant, I
mean stupid.

Yo da man bro! wassamatta dat gay mofo huh?

Chris Brown

2005-10-01 10:12:54 UTC

Post by Jeff R

Yo da man bro! wassamatta dat gay mofo huh?

And he answerde and seyde thus, "Madame,
I pray yow that ye take it nat agrief.
By God, me thoughte I was in swich meschief
Right now, that yet myn herte is soore afright.
Now God," quod he, "my swevene recche aright,
And kepe my body out of foul prisoun.
Me mette how that I romed up and doun
Withinne our yeerd, wheer as I saugh a beest
Was lyk an hound, and wolde han maad areest
Upon my body, and han had me deed.
His colour was bitwixe yelow and reed

Jeff R

2005-10-01 14:18:50 UTC

Post by Jeff R

Yo da man bro! wassamatta dat gay mofo huh?

But first I make a protestacioun
That I am dronke, I knowe it by my soun;
And therfore, if that I mysspeke or seye,
Wyte it the ale of Southwerk I you preye,
Wottthefork's goin' down here todeye?

Nostrobino

2005-10-01 14:23:00 UTC

Your entire diatribe about language and word usage is then,
according to the above, *stupid*.
Language *is* dynamic.

Hogwash. You are suggesting we should all be speaking Chaucer's
English.

No. We speak Modern English. Chaucer wrote, and presumably spoke, Middle
English. Even Modern English has changed since Shakespeare's time, but
that's over a period of 400 years. Evolution of language is inevitable and
natural up to a point, but it's not evolution when a perfectly sensible
technical term is, through misunderstanding and/or ignorance, redefined in a
nonsensical manner. Evolution implies improvement, not deterioration.

N.

no_name

2005-09-29 12:50:13 UTC

Post by Siddhartha Jain

I am aware of the mis-usage of the term *prime* and so guilty of
propogating the mis-usage but I feel its time the FFL camp realised
that there is no turning back.

Well, not necessarily, though of course the more people who misuse the term,
the harder it will be to correct it.
Most people do not want to use wrong terminology since it makes them look
ignorant. In the case of "prime" being used to mean FFL, this has only
spread because readers who have not seen the term before, and then see it
used by people they assume are knowledgeable, naturally adopt it themselves.
Thus newbies are caught up in the misusage and (perhaps partly because they
feel using jargon will make them look knowledgeable too), contribute to the
spread.
Some will continue to use it anyway, but others will drop it (and some have
dropped it) when the error is pointed out to them.
N.

Just because "popular usage" may not appear in a particular dictionary
does not constitute "misuse".

If you speak of a prime lens to photographers, they know what you're
talking about.

Perhaps this should be continued in rec.english.language.anal.purists

Nostrobino

2005-09-30 16:28:44 UTC

[ . . . ]

Post by no_name
Just because "popular usage" may not appear in a particular dictionary
does not constitute "misuse".
If you speak of a prime lens to photographers, they know what you're
talking about.

The problem is, they may not. I do sometimes have occasion to mention "prime
lens" and I assure you I use it correctly. People who think it means fixed
focal length will, therefore, not understand what I am saying.

N.

no_name

2005-09-30 23:26:39 UTC

Post by Nostrobino
[ . . . ]

Oh-ho, so that's it. Anyone who doesn't instantly understand your
feverish babble is an ignorant, "semi-literate ... whose
grasp of language is feeble"

Thank you for playing. You ARE the weakest link. Goodbye.

Floyd Davidson

2005-10-01 01:52:02 UTC

Post by no_name
Just because "popular usage" may not appear in a particular
dictionary does not constitute "misuse".
If you speak of a prime lens to photographers, they know what
you're talking about.

The problem is, they may not. I do sometimes have occasion to
mention "prime lens" and I assure you I use it
correctly. People who think it means fixed focal length will,
therefore, not understand what I am saying.
N.

Oh-ho, so that's it. Anyone who doesn't instantly understand your
feverish babble is an ignorant, "semi-literate ... whose
grasp of language is feeble"
Thank you for playing. You ARE the weakest link. Goodbye.

Isn't that a fascinating demonstration of how asinine humans can
be? The purpose of language is to communicate, but what
Nostrobino communicates is not what he thinks, but rather *how*
he thinks... people don't walk off with knowledge of what he
meant to say, only with an understanding that he won't say it.
Strange...

--
FloydL. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska) ***@apaflo.com

Nostrobino

2005-10-01 14:26:16 UTC

Post by Nostrobino
[ . . . ]

The problem is, they may not. I do sometimes have occasion to mention
"prime lens" and I assure you I use it correctly. People who think it
means fixed focal length will, therefore, not understand what I am
saying.
N.

Oh-ho, so that's it. Anyone who doesn't instantly understand your feverish
babble is an ignorant, "semi-literate ... whose
grasp of language is feeble"
Thank you for playing. You ARE the weakest link. Goodbye.

<GUFFAW!>

Your taste in TV shows explains a lot!

N.

Chris Brown

2005-09-30 10:57:56 UTC

I know this may give you apoplexy, but my nice shiny EOS 5D which I bought
yesterday includes, in the box, an accessories catalogue from Canon, which
amongst other things features a complete list of their current EF lens
range. They split it up into the following categories (from memory):

Zoom
Macro
Tilt and Shift
and, yes, Prime, which lists all of their fixed-focal length lenses (apart
from the Macros and T&S).

So at least one manufacturer is using the term to mean fixed-focal length.

Peter

2005-09-30 13:28:55 UTC

Post by Chris Brown
I know this may give you apoplexy, but my nice shiny EOS 5D which I bought
yesterday includes, in the box, an accessories catalogue from Canon, which
amongst other things features a complete list of their current EF lens
Zoom
Macro
Tilt and Shift
and, yes, Prime, which lists all of their fixed-focal length lenses (apart
from the Macros and T&S).
So at least one manufacturer is using the term to mean fixed-focal length.

I am willing to bet that some (possibly all) of the "macro" lenses
in the brochure are not really macro lenses intended primarily for
1:1 and greater magnification.

I would not be even slightly surprised if the word "telephoto" were
used more than once in the brochure to describe something that is
not actually a telephoto lens.

If you get your terminology from advertising literature, you are
probably going to get it wrong.

Peter.

--
***@ktb.net

Chris Brown

2005-09-30 13:43:37 UTC

Post by Chris Brown
Macro
Tilt and Shift
and, yes, Prime, which lists all of their fixed-focal length lenses (apart
from the Macros and T&S).
So at least one manufacturer is using the term to mean fixed-focal length.

I am willing to bet that some (possibly all) of the "macro" lenses
in the brochure are not really macro lenses intended primarily for
1:1 and greater magnification.

Actally they are. Canon have lots of lenses with so-called "Macro" zones on
their focus ring, which aren't actually 1:1, but AFAIK all the lenses in the
"Macro" category are true 1:1 or greater lenses.

Post by Peter
I would not be even slightly surprised if the word "telephoto" were
used more than once in the brochure to describe something that is
not actually a telephoto lens.

If you're going to object to the "misuse" of telephoto, you're fighting a
cause which is even more lost than the "prime" caus. I rather suspect that
the vast majority of non-LF photographers don't actually even understand
that it ever had a different meanning to its current one. What woul dyou
have people call what the whole world and their granny now calls "telephoto"
lenses? Narrow-angle, perhaps?

Post by Peter
If you get your terminology from advertising literature, you are
probably going to get it wrong.

If you want to be prescriptive about language, then you're off to a really
bad start by chosing English to fight your battle in. Perhaps you'd have
better luck with Latin?

Peter

2005-09-30 14:41:53 UTC

Post by Peter
I am willing to bet that some (possibly all) of the "macro" lenses
in the brochure are not really macro lenses intended primarily for
1:1 and greater magnification.

I think you misunderstand me. A _real_ macro lens is not one
which has a focus ring which goes up to 1:1, but a lens which
is primarily intended for 1:1 or greater magnification.

Real macro lenses have names on them like:
Leica (or Leitz) Photar
Leitz Micro-Summar (old)
Carl Zeiss Luminar
Carl Zeiss Jena Mikrotar
B&L Micro-Tessar (old)
Nikon (or Nippon Kogaku) Macro-Nikkor

They usually have no focusing ring and very often have the
same thread mount as microscope objectives. The old Leitz
Micro-Summars and B&L Micro-Tessars can often be had
quite cheaply, the modern ones tend to be very expensive.

Nikon is unusual in that they reserve the word "macro" for their
true macro lenses. Nikon uses "Micro-Nikkor" for their lenses
designed for normal close-up work.

Post by Peter
I would not be even slightly surprised if the word "telephoto" were
used more than once in the brochure to describe something that is
not actually a telephoto lens.

Narrow-angle it could be, and I have seen it used, but the normal
expression is "long-focus lens." As I posted in another part of
this thread, Olympus has made compact 35mm cameras for years which
have 35mm telephoto lenses on them which are thus both wide-angle
and telephoto. I know the lens on the Olympus XA was like this and
I believe it is also true for the Stylus Epic.

Post by Peter
If you get your terminology from advertising literature, you are
probably going to get it wrong.

If you want to be prescriptive about language, then you're off to a really
bad start by chosing English to fight your battle in. Perhaps you'd have
better luck with Latin?

Some battles in camera language have been won by the purists.
It used to be really common in the first half of the twentieth
century to use "Depth of Focus" incorrectly for the depth on the
object side of the lens. The purists won, and practically everyone
gets the "depth of field" vs. "depth of focus" distinction correct
nowadays. If you doubt me on this, look in a Leica Manual from
1935 to 1947 where the writers get the terminology wrong. In the
1951 and later editions, as well as almost any modern photography
book, the terms are used correctly.

Peter.

--
***@ktb.net

Peter

2005-09-30 16:12:14 UTC

Peter wrote:

I just looked it up and Canon does indeed make real macro lenses
with the inscription "Canon Macro Photo Lens." If those are
the lenses under "macro" in the catalogue then I apologize,
they are _real_ macro lenses.

Post by Peter
Nikon is unusual in that they reserve the word "macro" for their
true macro lenses. Nikon uses "Micro-Nikkor" for their lenses
designed for normal close-up work.

Canon uses "macro" on both their real macro lenses and their
not-quite macro lenses. The words "macro photo lens" seem to
be reserved for their true macro lenses.

Peter.

--
***@ktb.net

Paul J Gans

2005-09-30 19:58:54 UTC

I am willing to bet that some (possibly all) of the "macro" lenses
in the brochure are not really macro lenses intended primarily for
1:1 and greater magnification.
I would not be even slightly surprised if the word "telephoto" were
used more than once in the brochure to describe something that is
not actually a telephoto lens.
If you get your terminology from advertising literature, you are
probably going to get it wrong.

Again, that's probably right. But when you walk into a
store to buy one of those Canon lenses, would it not help
to call it what the manufacturer calls it?

----- Paul J. Gans

Peter

2005-09-30 22:26:57 UTC

Post by Paul J Gans
Again, that's probably right. But when you walk into a
store to buy one of those Canon lenses, would it not help
to call it what the manufacturer calls it?
----- Paul J. Gans

Of course you do. I think you may somehow be confounding me with
Neil H. I ain't him. I've got nothing against using slang, or
whatever you want to call improper terminology if it gets the
job done. I do think it is important to make a distinction between
proper technical terminology and slang so that when you have
a technical discussion you can communicate efficiently and with
precision.

For instance, the statement:

"In macro work the depth of focus is as large or larger than the
depth of field."

is a rather concise statement of an important fact. If we did not
have precise technical language, it would take considerably longer
to say the same thing and it still might not be as clear.

Another example:

"When doing closeups with a telephoto lens you need to include
pupil magnification in your bellows-factor calculations"

This is something worth knowing. If you have ever used a
retrofocus lens reverse mounted on a bellows on a camera
without a built-in light meter (I have) you might think
it a vital piece of information.

Try to say the same thing without using technical terms with
well defined meanings. There is good reason why telephoto
is not a synonym for long-focus lens, macro starts when the
image size is at least equal to object size, and close-up
photography starts at 1/10th life size when bellows factor
starts to be significant. The reason is that the terms are
defined as they are for the convenience of people discussing
photography in a technical way. The idea that the meanings
should change with fashion makes nonsense of the reasons for
having technical vocabulary in the first place.

Peter.

--
***@ktb.net

Nostrobino

2005-10-01 14:41:59 UTC

"Peter" <***@ktb.net> wrote in message news:***@g44g2000cwa.googlegroups.com...
[ . . . ]

Post by Peter
The reason is that the terms are
defined as they are for the convenience of people discussing
photography in a technical way. The idea that the meanings
should change with fashion makes nonsense of the reasons for
having technical vocabulary in the first place.

Well and truly said.

N.

Nostrobino

2005-09-30 16:44:15 UTC

I know this may give you apoplexy, but my nice shiny EOS 5D which I bought
yesterday includes, in the box, an accessories catalogue from Canon, which
amongst other things features a complete list of their current EF lens
Zoom
Macro
Tilt and Shift
and, yes, Prime, which lists all of their fixed-focal length lenses (apart
from the Macros and T&S).
So at least one manufacturer is using the term to mean fixed-focal length.

That is *NOT* how Canon categorizes them on their web site:

http://consumer.usa.canon.com/ir/controller?act=ProductCatIndexAct&fcategoryid=111

There, as you can see, they separate EOS lenses into these categories:

Ultra-Wide Zoom
Standard Zoom
Telephoto Zoom
Wide-Angle
Standard & Medium Telephoto
Telephoto
Super Telephoto
Macro
Tilt-Shift

And no mention of "prime" in any way, shape, manner or form.

But there is no question that the misuse has crept into what *should* be
responsible and even authoritative areas. In the past couple of years I have
seen "prime" misused (maybe two or three times) by caption writers in Pop
Photo, though the mistake was not repeated in the actual editorial content.
There have been a few other examples too.

The cases so far have been few and relatively isolated. There's no reason
the disease cannot be eradicated. We stamped out smallpox, didn't we?

N.

Eric Miller

2005-09-28 18:07:25 UTC

Post by Nostrobino
Zoom lenses ARE prime lenses, notwithstanding the now-popular misusage of
"prime."
A prime lens is the camera lens as distinct from some other lens or
lenticular device (close-up lens, tele converter, etc.) used with it. It
has meant that since long before zoom lenses became commonplace, and
therefore no need to use another term to mean "non-zoom."
"Prime" is properly used in the sense of primary, main, chief or
original--all dictionary definitions for "prime."
There is NO dictionary definition for "prime" which means fixed focal
length or single focal length, or fixed or single anything else.
It would be nice if this nonsensical misusage, which obviously is based on
someone's misunderstanding of the term some years ago (and then spread
like cancer through the power of the Internet) could be stamped out.
Surely "FFL" is at least as easy to type as "prime" anyway, and there
never was any reason other than shortness to replace "fixed focal length"
with the incorrect term.
N.

Many now accepted meanings of words have been created through misusage.
Perhaps you would prefer a dead language to English?

Eric Miller

Nostrobino

2005-09-30 16:51:06 UTC

Post by Eric Miller

Post by Nostrobino
Zoom lenses ARE prime lenses, notwithstanding the now-popular misusage of
"prime."
A prime lens is the camera lens as distinct from some other lens or
lenticular device (close-up lens, tele converter, etc.) used with it. It
has meant that since long before zoom lenses became commonplace, and
therefore no need to use another term to mean "non-zoom."
"Prime" is properly used in the sense of primary, main, chief or
original--all dictionary definitions for "prime."
There is NO dictionary definition for "prime" which means fixed focal
length or single focal length, or fixed or single anything else.
It would be nice if this nonsensical misusage, which obviously is based
on someone's misunderstanding of the term some years ago (and then spread
like cancer through the power of the Internet) could be stamped out.
Surely "FFL" is at least as easy to type as "prime" anyway, and there
never was any reason other than shortness to replace "fixed focal length"
with the incorrect term.
N.

Many now accepted meanings of words have been created through misusage.

Yes. The unfortunate thing is that some people think this is evolution, when
in fact it is deterioration. "Accepted meanings of words" now are sometimes
even the reverse of the actual meanings. For example, many people think "hoi
polloi" means the wealthy upper class.

Post by Eric Miller
Perhaps you would prefer a dead language to English?

No, English is great. If I didn't care for it so much I wouldn't be trying
to defend it.

N.

Tony Polson

2005-09-28 20:52:41 UTC

Post by Nostrobino
It would be nice if this nonsensical misusage, which obviously is based on
someone's misunderstanding of the term some years ago (and then spread like
cancer through the power of the Internet) could be stamped out.

The use, or misuse, of the term "prime" is nothing new. The same
discussion was around in the 1960s and 70s. It wasn't resolved then
and probably never will be.

So don't blame the Internet. Blame the manufacturers who chose to use
this term as a marketing tool at various times in the last 50 years.

;-)

Eugene

2005-09-28 23:24:43 UTC

Yes, I'm sure the missuse of the term "prime lens" will go down in
history as one of the greatest tragedies of our generation ;-)

Post by Nostrobino
Zoom lenses ARE prime lenses, notwithstanding the now-popular misusage of
"prime."

Eugene

2005-09-29 00:45:13 UTC

Just some links you may want to check out...

http://photonotes.org/cgi-bin/entry.pl?id=Primelens
http://en.wikipedia.org/wiki/Prime_lens
http://www.absoluteastronomy.com/encyclopedia/p/pr/prime_lens.htm

Please stop spreading misinformation. The first usage of a term is not
necessarily the correct one. If you start referring to zooms as "prime"
you're just going to make yourself sound stupid. Whatever you think it
meant originally, is not what it means now.

Jeff R

2005-09-29 00:59:29 UTC

Post by Eugene
Just some links you may want to check out...
http://photonotes.org/cgi-bin/entry.pl?id=Primelens
http://en.wikipedia.org/wiki/Prime_lens
http://www.absoluteastronomy.com/encyclopedia/p/pr/prime_lens.htm
Please stop spreading misinformation. The first usage of a term is not
necessarily the correct one. If you start referring to zooms as "prime"
you're just going to make yourself sound stupid. Whatever you think it
meant originally, is not what it means now.

Totally sick post, bro'! Hectic!
What a gay idea!

Peter

2005-09-29 03:56:27 UTC

No, but it can be good to distinguish between slang terminology
and standard terminology.

For instance, in audio people often talk about "acetate masters"
when they mean "lacquer originals." The slang terminology is
wrong on two counts because the originals of disc recordings
are made on cellulose nitrate lacquer and never acetate and they
are originals, not masters, according to long established terminology.
The use of the slang "acetate master" has caused very little real
confusion over the 70 years in which it has been in common use,
but it is still not correct because the disc is neither made
of acetate nor a master. (Wikipedia gets the definition of
"master recording" wrong, so I don't think it is a very good
source for standard technical vocabulary.)

An example in photography is the use of the word "macro"
as a synonym for "extreme close-up." Photomacrography,
from which we get "macro," has a very well established
technical meaning requiring the image size to be equal to
or larger than the object size. The Wikipedia article
"Macro Photography" starts out with the standard definition
which it calls the "classical definition" and then goes
on to discuss the extended use of the term in photographers'
slang without being particularly clear that the extended
meaning is still non-standard terminology. BTW it is better
to use "photomacrography" than "macro photography" since
"macrophotography" can mean the making of large photographs
by analogy with the difference between "photomicrography"
and "microphotography" which should never be confused with
each other.

The use of "prime lens" for "fixed focal length lens" appears
to originate in cinema where the need for a handy term
for a non-zoom lens was felt long before such a term was
needed in still photography. As a handy bit of slang, it
has much to recommend it: it is easy to say and quickly
understood. As a technical term, it has two major difficulties:
the word "prime" has little connection to what is meant,
and there was a prior use of the term in which the word
"prime" actually made sense.

Post by Eugene
If you start referring to zooms as "prime" you're just going
to make yourself sound stupid.

No, because you would always also be using an additional term
such as "supplementary lens" or "teleconverter" which would
supply the context which would make the meaning clear.

Post by Eugene
Whatever you think it meant originally, is not what it means now.

You know, sometimes words have two meanings.

Most of us can live with slang terminology and standard technical
terminology without getting particularly confused. Slang terminology
can be very handy: I'm not going to stop saying "Hypo" when I know
that fixer is actually thiosulphate. It isn't very likely that someone
will think I mean the actual chemical "sodium hyposulphite" AKA
"sodium hydrosulphite" which is AFAIK not used in photography.
But it is still good to distinguish between slang and proper technical
language. If I ordered "sodium hyposulphite" from a chemical supplier
who served dyers it is just possible I might get the wrong chemical.

Peter.

--
***@ktb.net

Brion K. Lienhart

2005-09-29 05:19:42 UTC

Post by Peter
You know, sometimes words have two meanings.
Most of us can live with slang terminology and standard technical
terminology without getting particularly confused. Slang terminology
can be very handy: I'm not going to stop saying "Hypo" when I know
that fixer is actually thiosulphate. It isn't very likely that someone

Not to be pedantic, but I think you mean "Jargon" not "Slang".

Peter

2005-09-29 14:17:53 UTC

Post by Brion K. Lienhart

Not to be pedantic, but I think you mean "Jargon" not "Slang".

Actually you are being pedantic, saying "not to be pedantic"
in front of a sentence doesn't make it so.

I looked up "slang" and "jargon" in several dictionaries,
and at least some of the meanings are nearly interchangable.
I chose "slang" because I wanted to emphasize the non-standard
nature of the vocabulary rather than any lack of intelligibility
to outsiders.

Peter.

--
***@ktb.net

Eugene

2005-09-29 07:17:31 UTC

Post by Peter
The use of "prime lens" for "fixed focal length lens" appears
to originate in cinema where the need for a handy term
for a non-zoom lens was felt long before such a term was
needed in still photography. As a handy bit of slang, it
has much to recommend it: it is easy to say and quickly
the word "prime" has little connection to what is meant,
and there was a prior use of the term in which the word
"prime" actually made sense.

OK, fair enough. You make a valid point, but in the case of "prime
lens", given the definition of the word, I don't think it's nescessarily
incorrect or ambiguous. Shortening complex expressions is just how
language works. Just a few other slang photographic terms I could think
of would be "film", or "sensor", or "flash", or even "lens". Everyone
knows what these terms mean, although none of them is strictly correct
or complete.

Post by Eugene
If you start referring to zooms as "prime" you're just going
to make yourself sound stupid.

No, because you would always also be using an additional term
such as "supplementary lens" or "teleconverter" which would
supply the context which would make the meaning clear.

Perhaps my comments were a bit harsh. I just took offense to the
suggestion that it was ignorant to use the widely accepted and
understood term "prime lens". It seemed clear that the Nostrobino was
just being undully pedantic and argumentative, and his comments added
nothing to the thread.

Post by Eugene
Whatever you think it meant originally, is not what it means now.

You know, sometimes words have two meanings.
Most of us can live with slang terminology and standard technical
terminology without getting particularly confused. Slang terminology
can be very handy: I'm not going to stop saying "Hypo" when I know
that fixer is actually thiosulphate. It isn't very likely that someone
will think I mean the actual chemical "sodium hyposulphite" AKA
"sodium hydrosulphite" which is AFAIK not used in photography.
But it is still good to distinguish between slang and proper technical
language. If I ordered "sodium hyposulphite" from a chemical supplier
who served dyers it is just possible I might get the wrong chemical.

As an Australian I certainly have no problem with slang ;-) Mind you
when I'm writing things for an international audience I'm careful to
avoid terms that will confuse people in other parts of the world. If I
wrote the way I would typically talk to other Aussies then a lot of
people wouldn't know what I was talking about. I hardly think though
that "prime lens" is one of those confusing obscure slang expressions.
Everyone knows what it means.

Tony Polson

2005-09-29 09:15:46 UTC

Post by Eugene
Perhaps my comments were a bit harsh. I just took offense to the
suggestion that it was ignorant to use the widely accepted and
understood term "prime lens".

But "prime lens" is NOT a "widely accepted and understood term".

Because of the history of its use, it is essentially ambiguous. It
has only been used as a descriptor for all fixed focal length lenses
in recent times, and only by people who are unaware of its prior
usage, which was as a descriptor for a "high quality" subset of fixed
focal length lenses. You might be too young to recall this.

There was no accepted definition of which fixed focal length lenses
were "prime" and which were not. It was merely an attempt by
marketing people to promote some lenses as being "better" than others,
the implication being that one brand was "better" than another because
of the "high quality" of their "prime" lenses.

The terms "high quality", "better" and "prime" are all essentially
meaningless unless backed up with something more objective, repeatable
and reliable. As we all (should) know, comparisons between lenses are
qualitative at best.

The most commonly used "objective" comparator - MTF - was never
intended for making such comparisons. It was intended as an aid to
lens designers and nothing more. As a result it misleads far more
than it ever informs, and those who claim it is of any real value when
comparing photographic lenses are suffering from delusions.

no_name

2005-09-29 12:57:18 UTC

Post by Eugene
Perhaps my comments were a bit harsh. I just took offense to the
suggestion that it was ignorant to use the widely accepted and
understood term "prime lens".

But "prime lens" is NOT a "widely accepted and understood term".

Who here does not understand what is meant when the term "prime lens" is
used?

A show of hands please?

David Littlewood

2005-09-29 16:12:38 UTC

Post by Eugene
Perhaps my comments were a bit harsh. I just took offense to the
suggestion that it was ignorant to use the widely accepted and
understood term "prime lens".

But "prime lens" is NOT a "widely accepted and understood term".

Who here does not understand what is meant when the term "prime lens"
is used?
A show of hands please?

As it is an ambiguous usage, i.e. one which is in conflict with the
traditional meaning of the word, then I personally avoid using the word
altogether. I agree that when others use the word it is usually apparent
from the context what they mean, but IMO it is mildly rude to one's
readers to deliberately choose to make them work out meaning from the
context.

David

--
David Littlewood

David Littlewood

2005-09-29 16:09:50 UTC

Post by Eugene
Perhaps my comments were a bit harsh. I just took offense to the
suggestion that it was ignorant to use the widely accepted and
understood term "prime lens".

But "prime lens" is NOT a "widely accepted and understood term".
Because of the history of its use, it is essentially ambiguous. It
has only been used as a descriptor for all fixed focal length lenses
in recent times, and only by people who are unaware of its prior
usage, which was as a descriptor for a "high quality" subset of fixed
focal length lenses. You might be too young to recall this.
There was no accepted definition of which fixed focal length lenses
were "prime" and which were not. It was merely an attempt by
marketing people to promote some lenses as being "better" than others,
the implication being that one brand was "better" than another because
of the "high quality" of their "prime" lenses.
The terms "high quality", "better" and "prime" are all essentially
meaningless unless backed up with something more objective, repeatable
and reliable. As we all (should) know, comparisons between lenses are
qualitative at best.
The most commonly used "objective" comparator - MTF - was never
intended for making such comparisons. It was intended as an aid to
lens designers and nothing more. As a result it misleads far more
than it ever informs, and those who claim it is of any real value when
comparing photographic lenses are suffering from delusions.

I agree with the first part of the above. The only point in which my
understanding differs is that the traditional use of the term "prime"
was in the sense of "primary" as opposed to secondary or auxiliary
optical components such as tele-converters, wide angle attachments,
close up lenses and the like. Thus prime as in the Latin "primus", first
or primary.

This is the interpretation given in the more rigorous works on
photography I consulted on this issue when the point was debated here
(ad nauseam) several years ago. (Anyone remember Neil Harrington?)

David

--
David Littlewood

Nostrobino

2005-09-30 18:02:17 UTC

Post by David Littlewood

Post by Eugene
Perhaps my comments were a bit harsh. I just took offense to the
suggestion that it was ignorant to use the widely accepted and
understood term "prime lens".

But "prime lens" is NOT a "widely accepted and understood term".
Because of the history of its use, it is essentially ambiguous. It
has only been used as a descriptor for all fixed focal length lenses
in recent times, and only by people who are unaware of its prior
usage, which was as a descriptor for a "high quality" subset of fixed
focal length lenses. You might be too young to recall this.
There was no accepted definition of which fixed focal length lenses
were "prime" and which were not. It was merely an attempt by
marketing people to promote some lenses as being "better" than others,
the implication being that one brand was "better" than another because
of the "high quality" of their "prime" lenses.
The terms "high quality", "better" and "prime" are all essentially
meaningless unless backed up with something more objective, repeatable
and reliable. As we all (should) know, comparisons between lenses are
qualitative at best.
The most commonly used "objective" comparator - MTF - was never
intended for making such comparisons. It was intended as an aid to
lens designers and nothing more. As a result it misleads far more
than it ever informs, and those who claim it is of any real value when
comparing photographic lenses are suffering from delusions.

I agree with the first part of the above. The only point in which my
understanding differs is that the traditional use of the term "prime" was
in the sense of "primary" as opposed to secondary or auxiliary optical
components such as tele-converters, wide angle attachments, close up
lenses and the like. Thus prime as in the Latin "primus", first or
primary.
This is the interpretation given in the more rigorous works on photography
I consulted on this issue when the point was debated here (ad nauseam)
several years ago. (Anyone remember Neil Harrington?)

I do!

I see him every time I shave. :-)

N.

David Littlewood

2005-09-30 18:34:03 UTC

Post by David Littlewood
I agree with the first part of the above. The only point in which my
understanding differs is that the traditional use of the term "prime" was
in the sense of "primary" as opposed to secondary or auxiliary optical
components such as tele-converters, wide angle attachments, close up
lenses and the like. Thus prime as in the Latin "primus", first or
primary.
This is the interpretation given in the more rigorous works on photography
I consulted on this issue when the point was debated here (ad nauseam)
several years ago. (Anyone remember Neil Harrington?)

I do!
I see him every time I shave. :-)
N.

Oh, Hi Neil!

David

--
David Littlewood

Nostrobino

2005-10-01 14:27:33 UTC

Post by David Littlewood

I do!
I see him every time I shave. :-)
N.

Oh, Hi Neil!
David
--
David Littlewood

Hi David!

N.

Nostrobino

2005-09-30 17:59:17 UTC

Sure, but where's the "shortening complex expressions" in this misusage? No
amount of shortening (or even Crisco) will make "prime" out of "fixed focal
length."

Just a few other slang photographic terms I could think of would be
"film", or "sensor", or "flash", or even "lens". Everyone knows what these
terms mean, although none of them is strictly correct or complete.

Post by Eugene
If you start referring to zooms as "prime" you're just going
to make yourself sound stupid.

No, because you would always also be using an additional term
such as "supplementary lens" or "teleconverter" which would
supply the context which would make the meaning clear.

Perhaps my comments were a bit harsh. I just took offense to the
suggestion that it was ignorant to use the widely accepted and understood
term "prime lens".

It *is* ignorant to misuse a term which has a proper technical meaning. The
fact that the misusage is "widely accepted and understood" does not make it
less ignorant.

Examples abound. The news media commonly use "bullets" when they mean
cartridges. It's not an error that any literate shooter would make; you will
not see cartridges called "bullets" in any respectable shooting publication;
when such a publication says "bullets" it means bullets.

Likewise, "prime lens" has a specific meaning, i.e. the camera lens as
opposed to some other lens or lenticular device used with it. One does not
necessarily expect accuracy in terminology from the news media, which get a
lot of things wrong anyway. But shouldn't photographers who've been at it
for a while be reasonably literate when they talk about equipment?

It seemed clear that the Nostrobino was just being undully pedantic and
argumentative, and his comments added nothing to the thread.

Correcting a technical misusage is, I think, a useful thing to add to a
thread having to do with any sort of technology.

Post by Eugene
Whatever you think it meant originally, is not what it means now.

You know, sometimes words have two meanings.
Most of us can live with slang terminology and standard technical
terminology without getting particularly confused. Slang terminology
can be very handy: I'm not going to stop saying "Hypo" when I know
that fixer is actually thiosulphate. It isn't very likely that someone
will think I mean the actual chemical "sodium hyposulphite" AKA
"sodium hydrosulphite" which is AFAIK not used in photography.
But it is still good to distinguish between slang and proper technical
language. If I ordered "sodium hyposulphite" from a chemical supplier
who served dyers it is just possible I might get the wrong chemical.

As an Australian I certainly have no problem with slang ;-) Mind you when
I'm writing things for an international audience I'm careful to avoid
terms that will confuse people in other parts of the world. If I wrote the
way I would typically talk to other Aussies then a lot of people wouldn't
know what I was talking about. I hardly think though that "prime lens" is
one of those confusing obscure slang expressions. Everyone knows what it
means.

Well, everyone thinks they do, and some of us actually do. :-)

N.

Peter

2005-09-29 04:01:50 UTC

Post by Eugene
If you start referring to zooms as "prime" you're just going
to make yourself sound stupid.

No, because you would always also be using an additional term
such as "supplementary lens" or "teleconverter" which would
supply the context which would make the meaning clear.

Post by Eugene
Whatever you think it meant originally, is not what it means now.

--
***@ktb.net

Nostrobino

2005-09-30 17:14:32 UTC

Your sources are in error. Anyone can set up a web page which says anything,
and in this case you have pages repeating misinformation the authors
presumably obtained from other sources on the Internet, such as the
newsgroups where this misusage occurs. Doubtless there are web pages about
kidnappings by flying saucer which are about as reliable as the ones you
list.

Post by Eugene
Please stop spreading misinformation. The first usage of a term is not
necessarily the correct one. If you start referring to zooms as "prime"
you're just going to make yourself sound stupid. Whatever you think it
meant originally, is not what it means now.

You might want to explain that to lens manufacturers such as Schneider and
Zeiss, both of whom along with Arri and some others have catalogued variable
primes (i.e., prime lenses of variable focal length). They've been making
world-famous lenses for a hundred years or so, but perhaps aren't as
knowledgeable about proper terminology as you are.

Here's a current ad from Schneider Kreuznach,
http://www.schneideroptics.com/info/ads_&_brochures/pdf/vp.pdf

There are lots of others, but I recommend this one to you because it has
VARIABLE PRIME in nice, great big letters right at the top of the page.

N.

Post by Eugene

Post by Nostrobino
Zoom lenses ARE prime lenses, notwithstanding the now-popular misusage of
"prime."
A prime lens is the camera lens as distinct from some other lens or
lenticular device (close-up lens, tele converter, etc.) used with it. It
has meant that since long before zoom lenses became commonplace, and
therefore no need to use another term to mean "non-zoom."
"Prime" is properly used in the sense of primary, main, chief or
original--all dictionary definitions for "prime."
There is NO dictionary definition for "prime" which means fixed focal
length or single focal length, or fixed or single anything else.
It would be nice if this nonsensical misusage, which obviously is based
on someone's misunderstanding of the term some years ago (and then spread
like cancer through the power of the Internet) could be stamped out.
Surely "FFL" is at least as easy to type as "prime" anyway, and there
never was any reason other than shortness to replace "fixed focal length"
with the incorrect term.
N.

Jeremy Nixon

2005-10-01 07:51:55 UTC

Post by Nostrobino
Your sources are in error. Anyone can set up a web page which says anything,
and in this case you have pages repeating misinformation the authors
presumably obtained from other sources on the Internet, such as the
newsgroups where this misusage occurs. Doubtless there are web pages about
kidnappings by flying saucer which are about as reliable as the ones you
list.

Indeed, you can find a large number of supposedly-authoritative sources
about photography repeating the tale about light meters being calibrated
to 18% gray -- the fact that they aren't and never have been doesn't seem
to stop people from believing it.

--
Jeremy | ***@exit109.com

Nostrobino

2005-10-01 14:34:27 UTC

Post by Jeremy Nixon

Really? That's something I've always just accepted as true myself. Now
you've piqued my curiosity: how is the 18% tale wrong?

Isn't an 18% gray card really 18% gray? (I have one around here somewhere
but never thought to test its eighteen-percentness. :-) )

N.

John A. Stovall

2005-09-28 15:48:02 UTC

On 28 Sep 2005 07:33:55 -0700, "Siddhartha Jain"

Rule of Thumb: A prime at any focal length and wide open is better
than a zoom at any focal length wide open.

********************************************************

"In general, the art of government consists in taking as
much money as possible from one party of the citizens
to give to the other."

Voltaire (1764)

no_name

2005-09-29 13:00:14 UTC

Post by John A. Stovall
On 28 Sep 2005 07:33:55 -0700, "Siddhartha Jain"

Rule of Thumb: A prime at any focal length and wide open is better
than a zoom at any focal length wide open.

Except when it's not ... like a really well made fast zoom lens being
compared to a really poorly made slow prime lens.

Pete D

2005-09-30 03:38:29 UTC

Post by John A. Stovall
On 28 Sep 2005 07:33:55 -0700, "Siddhartha Jain"

Rule of Thumb: A prime at any focal length and wide open is better
than a zoom at any focal length wide open.

Except when it's not ... like a really well made fast zoom lens being
compared to a really poorly made slow prime lens.

So a Ferrari is faster than a Goggomobile, who'd of thought it??

Mark Roberts

2005-09-28 18:07:42 UTC

Post by Siddhartha Jain
Given two lenses, one a prime (say 28mm) and the other a zoom (say
28-75mm) and both with an aperture of f2.8 -
- Will the prime be brighter than the zoom because it has fewer lens
elements?
- Will the prime be sharper wide open than the zoom at 28mm?
Ofcourse, a lot will depend on the particular makes and models being
compared but is there a rule of thumb?

The rule of thumb is that it depends on the make and model.

--
Mark Roberts
Photography and writing
www.robertstech.com

Jeremy

2005-09-28 18:57:32 UTC

In theory, zooms will always be somewhat below the quality of prime lenses.
Zooms typically have barrel distortion at one end of the zoom range, and
pincushion distortion at the other. Older zooms, especially those that did
not have decent multicoating, were more prone to flare and ghosting, because
of the light bouncing back and forth off the air-to-glass surfaces.

The margin of superiority of primes over zooms has narrowed, and many
photographers find the convenience and economy of one zoom versus several
primes to be more important than some slight degree of image degradation. I
have a couple of Pentax zooms in K-mount that do a credible job, and it
certainly is easier to carry two zooms than it is to carry 5 or 6 primes.
Thirty years ago, I bought a couple of third-party zooms for my M43 bodies,
and the results were just awful, relative to my SMC Takumar prime lens.
Colors had a grayish cast, saturation was less than on the OEM lens, the
aperture ring was operated in the reverse direction of my Takumar's (Pentax
does it "backwards"), the front element turned when the focusing ring was
moved, making polarizer use difficult, the lens front element was not the
standard Takumar 49mm or 58mm, making it necessary to buy filters just for
use in that lens, and the resolution was noticeably less than that of the
OEM Takumar.

The build quality was obviously less-good than the OEM lens. The focusing
was not nearly as smooth, the zoom ring was a bit on the tight side, the
lens barrel was not as sturdy and the lens lacked multicoating (this was 30
years ago). So, while I saved a few dollars, I got pretty much what I paid
for and no more. I ended up putting that zoom lens up on the shelf, where
it remains to this day, and I bought only OEM lenses after that. They cost
a bit more, but the level of satisfaction that I derived from them made up
for the higher price. And not a single one of the OEM lenses has failed, in
3 decades.

British landscape photographer and author Brian Bower noted that, while his
Leica R zoom lenses cost a lot more than non-OEM lenses, he felt that they
were a good value because they retained their accuracy after over a decade
of hard use. He noted in one of his books that the cheaper zoom lenses
might see the elements go out of precise adjustment and the zoom mechanism
might become very loose after a time, making it necessary to keep checking
the zoom ring to be certain that the zoom ratio has not changed from
whatever it was originally set to. Bower valued consistently good results
more than lower price. He made his living with those tools, and he had
little tolerance for lens failures.

My own take on it is that if the proposed use of the lens is of a very
casual nature, it is probably okay to go for the savings. But if top
performance and reliability are paramount, one really has to think about
whether the savings might be offset by potential future loss from
poorly-performing equipment. I would rather have only a couple of really
good lenses than a kit full of lenses of questionable reliability and
performance. It seems that, in my own case, virtually every time I have
tried to save money by cutting corners I ended up paying double.

Cockpit Colin

2005-09-28 20:03:37 UTC

I've heard it suggested that may high quality zooms are visually
indistinguishable from their prime equivalents - however both can usually
out-perform most photographers!

J***@no.komm

2005-09-29 00:31:30 UTC

Post by Cockpit Colin
I've heard it suggested that may high quality zooms are visually
indistinguishable from their prime equivalents

You can always bring out the difference in a large print or display, or
with teleconverters or extension tubes

Post by Cockpit Colin
- however both can usually
out-perform most photographers!

Not under good conditions.

--
<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>

Post by Cockpit Colin
<<> <>>< <>>< ><<> <>>< ><<> ><<> <>><

Dr. Joel M. Hoffman

2005-09-28 21:47:15 UTC

No. f/2.8 tells you exactly how bright the lens is. (It's almost
like the old question about a pound of lead and a pound of feathers -
they do both weigh the same.)

Post by Siddhartha Jain
- Will the prime be sharper wide open than the zoom at 28mm?

Probably, particuarly if both lenses are in the same price range. On
the other hand, there are lots of expensive zoom lenses that are
sharper than cheap fixed lenses.

-Joel

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Brion K. Lienhart

2005-09-29 05:23:36 UTC

Post by Dr. Joel M. Hoffman

No. f/2.8 tells you exactly how bright the lens is. (It's almost
like the old question about a pound of lead and a pound of feathers -
they do both weigh the same.)

Well, no. The F-stop is the ratio of the aperature to the focal length,
which is constant regardless of the actual material(s) of the glass. In
the extreme case of spraying black paint on the lens, you could have an
F:2.8 lens with 0% light transmission.

no_name

2005-09-29 13:01:41 UTC

Post by Dr. Joel M. Hoffman

No. f/2.8 tells you exactly how bright the lens is. (It's almost
like the old question about a pound of lead and a pound of feathers -
they do both weigh the same.)

However, a pound of gold and a pound of feathers do not.

Dave Martindale

2005-09-29 20:52:05 UTC

Post by Dr. Joel M. Hoffman
(It's almost
like the old question about a pound of lead and a pound of feathers -
they do both weigh the same.)

However, a pound of gold and a pound of feathers do not.

Due to the archaic system of weights&measures that uses a different unit
with the same name for measuring precious metals.

But a gram of gold and a gram of feathers *are* the same mass, and have
the same weight in the same gravity.

Dave

no_name

2005-09-30 03:41:30 UTC

Post by Dave Martindale

Post by Dr. Joel M. Hoffman
(It's almost
like the old question about a pound of lead and a pound of feathers -
they do both weigh the same.)

However, a pound of gold and a pound of feathers do not.

Due to the archaic system of weights&measures that uses a different unit
with the same name for measuring precious metals.
But a gram of gold and a gram of feathers *are* the same mass, and have
the same weight in the same gravity.
Dave

OTOH, "the old question" was weight not mass.

Randall Ainsworth

2005-09-29 02:20:22 UTC

F/2.8 lets the same amount of light through regardless of the lens
design. F/2.8 is f/2.8.

Being from the old school, I would expect a fixed focal length lens to
be sharper than a zoom, but you may have to go to laboratory conditions
to prove it.

Brion K. Lienhart

2005-09-29 05:29:43 UTC

Post by Randall Ainsworth

F/2.8 lets the same amount of light through regardless of the lens
design. F/2.8 is f/2.8.

Nope. F:2.8 is solely based on the size of the lens. Obsidian is glass,
you can grind it into a lens shape, but if you use it as an element in a
lens, you're going to get some reallllllly slow shutter speeds. Of
course that's an extreme case, the difference between plain old glass
glass, and exotic flouro-silicates is only a few fractions of a percent.

k***@sonic.net

2005-09-29 10:11:51 UTC

On Wed, 28 Sep 2005 22:29:43 -0700, "Brion K. Lienhart"

Post by Brion K. Lienhart

Post by Randall Ainsworth

F/2.8 lets the same amount of light through regardless of the lens
design. F/2.8 is f/2.8.

So what was your point in bringing up a special case ulikely
to be implemented?

Jan Böhme

2005-09-29 11:05:19 UTC

Post by k***@sonic.net
On Wed, 28 Sep 2005 22:29:43 -0700, "Brion K. Lienhart"
F:2.8 is solely based on the size of the lens. Obsidian is glass,

Post by Brion K. Lienhart
you can grind it into a lens shape, but if you use it as an element in a
lens, you're going to get some reallllllly slow shutter speeds. Of
course that's an extreme case, the difference between plain old glass
glass, and exotic flouro-silicates is only a few fractions of a percent.

So what was your point in bringing up a special case ulikely
to be implemented?

To illustrate the difference in principle between f-stop and t-stop in
an obviuos way, perhaps?

Jan Böhme

Randall Ainsworth

2005-09-29 12:44:02 UTC

Post by Brion K. Lienhart
Nope. F:2.8 is solely based on the size of the lens. Obsidian is glass,
you can grind it into a lens shape, but if you use it as an element in a
lens, you're going to get some reallllllly slow shutter speeds. Of
course that's an extreme case, the difference between plain old glass
glass, and exotic flouro-silicates is only a few fractions of a percent.

An f/2.8 lens is going to allow a specific amount of light to go
through regardless of what kind of glass it's made of.

W.E. O'Neil

2005-09-29 13:46:16 UTC

Post by Randall Ainsworth
An f/2.8 lens is going to allow a specific amount of light to go
through regardless of what kind of glass it's made of.

Strictly speaking you are on the wrong track. I think you may be confusing
transmission with focal ratio. F2.8 simply speaks to the focal
ratio.......slower materials would result in less light being transmitted.

Peter

2005-09-29 13:50:36 UTC

Post by Randall Ainsworth

An f/2.8 lens is going to allow a specific amount of light to go
through regardless of what kind of glass it's made of.

Actually no, but in most cases the difference is unimportant.

One case where the difference generally is important is with
a mirror lens. A mirror lens is generally only about 60%
efficient compared with around 90%+ efficiency for a glass
lens with ten multicoated air-glass surfaces.

A 500mm f/6.3 mirror lens may let in about the same light
as a 500mm f/8 coated glass lens. This can be a significant
factor when deciding what lens to buy. A mirror lens does
not gather quite as much light as you would expect from
the aperture.

Peter.

--
***@ktb.net

Scott Schuckert

2005-09-29 14:03:12 UTC

Post by Randall Ainsworth
An f/2.8 lens is going to allow a specific amount of light to go
through regardless of what kind of glass it's made of.

Ahem. Notice the previous 50+ responses in this thread? If not, read
some - you're dead wrong. What you're thinking of is a T-stop. Lenses
of the same mathematical aperture (f/stop) can and do wary widely in
transmission. Period.

Jeremy

2005-09-29 16:32:20 UTC

Post by Randall Ainsworth
An f/2.8 lens is going to allow a specific amount of light to go
through regardless of what kind of glass it's made of.

I believe that you are incorrect. the F-stops are geometric measurements of
the aperture opening. If a lens has a large number of elements, like a zoom
lens, less light may ultimately reach the film plane (or the chip) than
would be the case if a lens with a lesser number of elements were
substituted, even if both lenses were set to the same aperture opening.

My SMC Takumar 50mm f/1.4 is an interesting example. As is well known, the
rear element on those lenses had Thorium mixed into the optical glass
formula, and the decaying atomic particles have yellowed the lens over the
decades. That lens, set at f/1.4, probably transmits only an amount of
light equivalent to another (non-yellowed) lens at f/1.8.

I admit, however, that most lenses, at any given f-stop, probably transmit
about the same amount of light to the film or chip. But it is not
absolutely guaranteed. And these days, with TTL metering, the exposure
values can be adjusted to compensate.

Nostrobino

2005-09-30 18:41:31 UTC