question about 'APO' lens

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Archive 2009 · question about 'APO' lens

cheve
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p.1 #1 · question about 'APO' lens

All,

I have a number of questions on APO lens on 35mm SLR:

1. Are there any poor man version of 'APO' lens exist(ie. non-APO designated lens; but provide good correction)?

2. Are there any bad 'APO' lens? Bad is as in proivde good correction and yet 'soft' image.

3. Before 'APO' were invented/available; what did you do to compensate and/or to mininize the issue? Was post-processing the only route?

Thanks for your time.
Cheers

Jul 21, 2009 at 06:51 PM

olyacme
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p.1 #2 · question about 'APO' lens

cheve wrote:
All,

I have a number of questions on APO lens on 35mm SLR:

1. Are there any poor man version of 'APO' lens exist(ie. non-APO designated lens; but provide good correction)?

There sure are; by definition pinhole cameras are apochromatic.

cheve wrote:
2. Are there any bad 'APO' lens? Bad is as in proivde good correction and yet 'soft' image.

Yes. Apochromatic refers to spherical and chromatic aberration and, depending on the definition, coma. There are plenty more aberrations available to spoil your day.

cheve wrote:
3. Before 'APO' were invented/available; what did you do to compensate and/or to mininize the issue? Was post-processing the only route?

Apochromatism, as an aspiration by designers of telescopes and microscopes, dates to the 19th century at latest. It was limited to slow designs, or to designs that could employ (small) natural fluorite elements. Artificial fluorite and more lately fluoro-ED glass have made much larger and faster designs possible.

In microscopy, imaging under monochromatic light was a popular solution.

In astronomy, use of a "minus violet" filter to remove a typical achromat's most poorly corrected portion of the spectrum remains a popular solution.

BTW, precious few camera lenses marketed as "APO" are really anything close. Even if they were, there is far more to a good lens than perfect correction for spherochromatism.

Jul 21, 2009 at 07:20 PM

cheve
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p.1 #3 · question about 'APO' lens

There sure are; by definition pinhole cameras are apochromatic.

I was hoping for lens to go with more 'mainstream' like Canon, Nikon or etc system:-). Pinhole cameras sounds fun however.

...
In microscopy, imaging under monochromatic light was a popular solution.
...

I guess, it means(also by definition) that if I shoot B/W then I do not need to care.

...
In astronomy, use of a "minus violet" filter to remove a typical achromat's most poorly corrected portion of the spectrum remains a popular solution.
....

Is there similar 'filter' solution for non-astronomy photography?

Cheers

Edited on Jul 21, 2009 at 08:27 PM · View previous versions

Jul 21, 2009 at 08:15 PM

olyacme
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p.1 #4 · question about 'APO' lens

cheve wrote:

I was hoping for lens to go with more 'mainstream' like Canon, Nikon or etc system:-). Pinhole cameras sounds fun however.

Fast, cheap, and formal APO don't ever go together.

cheve wrote:
I guess, it means(also by definition) that if I shoot B/W then I do not need to care.

Unfortunately you'll still care. You just won't easily be able to tell the difference between CA and SA anymore.

cheve wrote:

...
In astronomy, use of a "minus violet" filter to remove a typical achromat's most poorly corrected portion of the spectrum remains a popular solution.
....

Is there similar 'filter' solution for non-astronomy photography?

Cheers

Not in colour photography, though for B&W this is absolutely a possibility. Just bear in mind that, even in B&W, only viewing a portion of the colour spectrum will still affect how the world is presented.

Jul 21, 2009 at 08:19 PM

cogitech
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p.1 #5 · question about 'APO' lens

olyacme wrote:

Fast, cheap, and formal APO don't ever go together.

I know of at least one exception. The CV 125/2.5 Macro APO-Lanthar is fairly fast for its focal length, was only $600 when released (relatively cheap) and it has excellent APO-correction (I see basically no LoCA or LaCA). On top of all that, it excels in many of the other qualities that make, as you say, "a good lens".

If there is one exception, maybe there are others?

Jul 21, 2009 at 08:32 PM

wayne seltzer
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p.1 #6 · question about 'APO' lens

cogitech wrote:
olyacme wrote:

Fast, cheap, and formal APO don't ever go together.

I know of at least one exception. The CV 125/2.5 Macro APO-Lanthar is fairly fast for its focal length, was only $600 when released (relatively cheap) and it has excellent APO-correction (I see basically no LoCA or LaCA). On top of all that, it excels in many of the other qualities that make, as you say, "a good lens".

If there is one exception, maybe there are others?

Yes, but current prices of the CV 125 (which are rare) are well over $1000, I've heard $1200-$1500 range, so I don't think you can call it cheap anymore.

Jul 21, 2009 at 08:38 PM

pdmphoto
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p.1 #7 · question about 'APO' lens

I've found late version of the Nikon 300/4.5 to very near APO in correction, but they are not labeled as such. Some say Nikon used ED glass in them before ED became a marketing buzzword.

The older Sigma 180/2.8 and 180/5.6 macro lenses are APO designated lenses, and perform as such. The Canon AF no longer have aperture control on newer EOS bodies (they do work fine wide open), but you can always get a Nikon (or other) mount version and use it on a Canon EOS camera with adapter. I have the 180/2.8 in a rare Nikon manual focus version, and it performs beautifully on my Kodak SLR/c and Canon 5DII.

Jul 21, 2009 at 08:44 PM

cheve
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p.1 #8 · question about 'APO' lens

can't justify a >1k lens for what I do(or do not do:-))...but does it mean there is still hope to get a 'cheap' and somewhat slow(eg. f4) but decent, 'APO'-like quality lens?

Jul 21, 2009 at 08:49 PM

olyacme
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p.1 #9 · question about 'APO' lens

cogitech wrote:
olyacme wrote:

Fast, cheap, and formal APO don't ever go together.

I know of at least one exception. The CV 125/2.5 Macro APO-Lanthar is fairly fast for its focal length, was only $600 when released (relatively cheap) and it has excellent APO-correction (I see basically no LoCA or LaCA). On top of all that, it excels in many of the other qualities that make, as you say, "a good lens".

If there is one exception, maybe there are others?

It may be apochromatic by f/5 or so, but that's not fast by photographic standards. Fast cheap and APO really are exclusive.

Jul 21, 2009 at 09:09 PM

jcolwell
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p.1 #10 · question about 'APO' lens

I recently picked up a new Mamiya M645 A 200/2.8 APO on eBay for $770 CA, shipping included. It's a beauty.

Jul 21, 2009 at 09:12 PM

Paul Yi
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p.1 #11 · question about 'APO' lens

CV Apo 90/3.5 can be had for less than $400....

Jul 21, 2009 at 09:13 PM

olyacme
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p.1 #12 · question about 'APO' lens

Paul Yi wrote:
CV Apo 90/3.5 can be had for less than $400....

Again, APO at f/3.5? Optimistic beyond belief. Given that the finest sensor you can commonly stick it on runs into Nyquist around f/5.6 or so it may not matter that it's only apochromatic when stopped down. But if you can't trust a manufacturer to say under exactly what terms a lens is apochromatic, how can you trust the designation at all?

Jul 21, 2009 at 09:17 PM

Conner999
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p.1 #13 · question about 'APO' lens

Pentax mount CV 90 APO (sweet, sweet glass) maybe for that, Nikon forget it. ;> (I know, because I've been doing some price research re: selling mine... The Elinchrom bug has firmly taken hold ;> or is it ;< ?)

Edited on Jul 21, 2009 at 09:23 PM · View previous versions

Jul 21, 2009 at 09:20 PM

Steve Spencer
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p.1 #14 · question about 'APO' lens

You can pick up a used Leica R APO 180mm f/3.4 for less than $1,000 and the Voigtlander APO 180mm f/4 can also be picked up for less than $1,000. Neither is very fast, but both are very nice lenses.

Jul 21, 2009 at 09:21 PM

cheve
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p.1 #15 · question about 'APO' lens

jcolwell wrote:
I recently picked up a new Mamiya M645 A 200/2.8 APO on eBay for $770 CA, shipping included. It's a beauty.

now, I know who picked up that item, I was looking at it awhile back but did not commit(my CFO was not in the good mood

)

Jul 21, 2009 at 09:25 PM

Toothwalker
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p.1 #16 · question about 'APO' lens

olyacme wrote:
It may be apochromatic by f/5 or so, but that's not fast by photographic standards. Fast cheap and APO really are exclusive.

How does the f-number affect the number of wavelengths that share a common focal plane?

Jul 21, 2009 at 10:04 PM

olyacme
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p.1 #17 · question about 'APO' lens

Toothwalker wrote:
olyacme wrote:
It may be apochromatic by f/5 or so, but that's not fast by photographic standards. Fast cheap and APO really are exclusive.

How does the f-number affect the number of wavelengths that share a common focal plane?

It lowers the bar (increases the size of the airy disk). A diffraction limited white light f/2.5 lens covering 135 format for $1000? Gimme a break!

Conversely, many (good) 135 lenses are diffraction limited by f/11-16, a sweet spot to be so on film. Of course, depending on the mix of aberrations, many (some still good) lenses will not cross the bar at any stop.

Jul 21, 2009 at 10:08 PM

Toothwalker
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p.1 #18 · question about 'APO' lens

olyacme wrote:
Toothwalker wrote:
How does the f-number affect the number of wavelengths that share a common focal plane?

It lowers the bar (increases the size of the airy disk). A diffraction limited white light f/2.5 lens covering 135 format for $1000? Gimme a break!

I don't make claims about any lens, I just ask how the f-number affects the number of zero crossings. See http://en.wikipedia.org/wiki/Apochromat for the definition of an apochromatic lens design. Stopping down the lens should not alter the number of wavelengths that are brought together in the same focal plane, unless you invoke some complex interaction with spherical aberration. Of course, residual color errors are reduced as the lens is stopped down, but that does not make an achromatic lens (or whatever) apochromatic.

Jul 21, 2009 at 11:07 PM

olyacme
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p.1 #19 · question about 'APO' lens

Toothwalker wrote:
I don't make claims about any lens, I just ask how the f-number affects the number of zero crossings. See http://en.wikipedia.org/wiki/Apochromat for the definition of an apochromatic lens design. Stopping down the lens should not alter the number of wavelengths that are brought together in the same focal plane, unless you invoke some complex interaction with spherical aberration. Of course, residual color errors are reduced as the lens is stopped down, but that does not make an achromatic lens (or whatever) apochromatic.

There are no zeros here. Aberrations are always present. The very best you can hope for is that they're so well corrected that they're hidden by diffraction (within the airy disk). Stopping the lens down increases the size of the airy disk, lowering the correction demanded to qualify as Apochromatic, while simultaneously reducing certain aberrations.

Jul 21, 2009 at 11:23 PM

cheve
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p.1 #20 · question about 'APO' lens

a lot info has been given for question 1 and 2, I would appreciate further comments for question 3

thanks and Cheers

PS: also enjoy reading http://stason.org/TULARC/recreation/photography/lenses-faq/index.html

Edited on Jul 21, 2009 at 11:39 PM · View previous versions

Jul 21, 2009 at 11:29 PM

olyacme
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p.1 #21 · question about 'APO' lens

cheve wrote:
a lot info has been given for question 1 and 2, I would appreciate further comments for question 3

IMO the best approach is to avoid situations where you know a lens performs poorly. If it's got a lot of field curvature, don't use it wide open at infinity. If it's got a lot of defocus CA, don't use it for closeups with a lot of detail in them. For CA in general, try to avoid hard light. Don't shoot into bright light if it flares. A lens that has a lot of Coma is probably a bad one to use for starfields, but it might be a great portrait lens.

Jul 21, 2009 at 11:32 PM

thrice
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p.1 #22 · question about 'APO' lens

The Cosina-Voigtlander 180/4 APO-Lanthar has no perceivable CA at least at any aperture across the entire frame. The Leica 100mm APO-Macro-Elmarit-R is almost as well corrected.

Reviews and sample images show the same thing, and I have seen it pixel peeping at my copies.

Jul 21, 2009 at 11:44 PM

cheve
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p.1 #23 · question about 'APO' lens

thanks olyacme, I guess it really comes down to:

1. know your lens
2. select the right lens for the situation

I guess this also give me "excuse" to get more (affordable) lens

Edited on Jul 21, 2009 at 11:53 PM · View previous versions

Jul 21, 2009 at 11:52 PM

cogitech
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p.1 #24 · question about 'APO' lens

olyacme wrote:
cogitech wrote:
olyacme wrote:

Fast, cheap, and formal APO don't ever go together.

I know of at least one exception. The CV 125/2.5 Macro APO-Lanthar is fairly fast for its focal length, was only $600 when released (relatively cheap) and it has excellent APO-correction (I see basically no LoCA or LaCA). On top of all that, it excels in many of the other qualities that make, as you say, "a good lens".

If there is one exception, maybe there are others?

It may be apochromatic by f/5 or so, but that's not fast by photographic standards. Fast cheap and APO really are exclusive.

I'm speaking of it's wide open performance. Have you used this lens?

Jul 21, 2009 at 11:52 PM

pdmphoto
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p.1 #25 · question about 'APO' lens

Cheve, if you look around you can find the Sigma 180/2.8 Macro for a few hundred. It's sharp and APO corrected from wide open. Even works beautifully with the Kenko/Tamron Pro 1.4x (from wide open).

Jul 21, 2009 at 11:54 PM


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