Dumb question: APO and monochrom

[Olaf_ZG]

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I read somewhere, here on LUF, that apo-lenses are irrelevant to monochrom cameras regarding the apo part. Is this correct? 

[thighslapper]

No. ..... as far as my interpretation is concerned. 

In theory non apochromatic lenses are softer and have less resolving power as the various wavelengths are not brought to a focus point in the same plane. 

Apo lenses are also generally better optically corrected all round as well as if you are going to completely correct chromatic and spherical aberrations you might as well deal with all the other optical obstacles as well....

Just how much difference it will make in practice is another matter entirely .....

 

[IkarusJohn]

Historically, APO was shorthand for apochromatic, meaning that different wavelengths (colours) were resolved by the lens so that they converged on the film plane at the same point - no colour blurring or shadowing on the film. On a black and white film, or sensor, you’d still get the colour separation, it would just be rendered as an monochromaticimage. The issue is more significant with telephoto lenses. I suspect most modern telephoto lenses are apochromatically corrected - they’d be pretty hopeless if they weren’t.

Leica’s APO designation is a branding exercise, usually signifying higher resolving power and better correction across the frame. Both the 50 Summilux ASPH and the 50 Noctilux 0.95 are APO lenses (as in apochromatic), but do not carry the designation.  It’s marketing really.

I have the 35 and 50 APO Summicrons, and they are great on the Monochrom.  If you search back through the forum, there was a lot of discussion when the 50 APO Summicron was released about whether you needed a higher resolving sensor to get the benefits of a higher resolving lens. Search @Olaf - he pointed out that a camera is a system - improve one element, and you improve the system, whether it’s the lens or the sensor. 

Edited June 30, 2023 by IkarusJohn

[Jeff S]

7 hours ago, IkarusJohn said:

Search @Olaf - he pointed out that a camera is a system - improve one element, and you improve the system, whether it’s the lens or the sensor. 

Roger Cicala wrote about this 4 years ago (see appendix to linked article) and has been cited ad nauseam since (recently by 01af, not Olaf).
 

https://www.lensrentals.com/blog/2019/10/more-ultra-high-resolution-mtf-experiments/

 

Jeff

 

Edited July 1, 2023 by Jeff S

[Guest]

4 years ago the APO Summicron M 35mm was not yet available. Too bad he did not test the APO Summicron M 50mm or the 50, 75, 90 SL lenses.

[Jeff S]

The concept applies generally.  Lensrentals, founded by Roger, still regularly tests lenses, sometimes Leica.  
 

They included the 50 APO M here..

https://www.lensrentals.com/blog/2016/10/the-ultimate-50mm-lens-comparison/

They also did a tear down on the SL 24-90..

https://www.lensrentals.com/blog/2016/02/a-peak-inside-the-leica-vario-elmarit-sl-24-90mm-f2-8-4-asph/

 

Jeff

 

 

Edited July 1, 2023 by Jeff S

[Jeff S]

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10 minutes ago, Jeff S said:

 

 

 

Deleted

Edited July 1, 2023 by Jeff S

[IkarusJohn]

1 hour ago, Jeff S said:

Roger Cicala wrote about this 4 years ago (see appendix to linked article) and has been cited ad nauseam since (recently by 01af, not Olaf).
 

https://www.lensrentals.com/blog/2019/10/more-ultra-high-resolution-mtf-experiments/

 

Jeff

 

Not being in the US, and not having access to Lensrentals, or any other rentals, or the ability to touch, let alone try before I buy, , Roger Cicala is off my radar.  I’m sure he has valuable contributions, but I do tend to try to share my direct experience, if I think it can be helpful.

Sorry if that has already been covered by others elsewhere.  It is just a conversation, isn’t it?

[Jeff S]

7 hours ago, IkarusJohn said:

Not being in the US, and not having access to Lensrentals, or any other rentals, or the ability to touch, let alone try before I buy, , Roger Cicala is off my radar.  I’m sure he has valuable contributions, but I do tend to try to share my direct experience, if I think it can be helpful.

Sorry if that has already been covered by others elsewhere.  It is just a conversation, isn’t it?

I was merely trying to provide him with the source material, which I linked, rather than send him on a wild goose chase. You directed him to find comments from Olaf.  He never made them; 01af did…two different people. And 01af quoted Roger as the basis of his comments, as others like me and Jaap have been quoting here for years. I guess you just haven’t followed these discussions, not just for US residents.  Even Jono, who you follow, published Roger’s article in his review of the M11 Monochrom ..

https://www.l-camera-forum.com/topic/375463-jono-slack-review-leica-m11-monochrome/

Jeff

Edited July 1, 2023 by Jeff S

[Olaf_ZG]

Boy, too many Olaf’s here. Thank you for feedback.

[Jeff S]

Here’s the relevant section from Roger’s article… again…

Appendix: Why Perceptual Megapixels are Stupid

I get asked several times a week if this lens or that is ‘capable of resolving’ this number of megapixels. Some people seem to think a lens should be ‘certified’ for a certain number of pixels or something. That’s not how it works. That’s not how any of it works.

How it does work is this. Any image you capture is not as sharp as reality. Take a picture of a bush and enlarge it to 100%. You probably can’t see if there are ants on the leaves. But in reality, you could walk over to the bush (enlarge it if you will) and see if there are ants by looking at a couple of leaves.

What if I got a better camera and a better lens? Well, theoretically, things would be so good I could see the ants if I enlarged the image enough. MTF is somewhat of a measurement of how sharp that image would be and how much detail it contains. (The detail part would be the higher frequency MTF.) That would, of course, be the MTF of the entire system, camera, and lens.

Lots of people think that will be ‘whichever is less of the camera and lens.’ For example, my camera can resolve 61 megapixels, but my lens can only resolve 30 megapixels, so all I can see is 30 megapixels.

That’s not how it works. How it does work is very simple math: System MTF = Camera MTF x Lens MTF. MTF maxes at 1.0 because 1.0 is perfect. So let’s say my camera MTF is 0.7, and my lens MTF is 0.7, then my system MTF is 0.49 (Lens MTF x Camera MTF). This is actually a pretty reasonable system.

Now, let’s say I get a much better camera with much higher resolution; the camera MTF is 0.9. The system MTF with the same lens also increases: 0.7 X 0.9 = 0.63. On the other hand, I could do the same thing if I bought a much better lens and kept it on the same camera. The camera basically never ‘out resolves the lens.’

You could kind of get that ‘perceptual megapixel’ thing if either the lens (or the camera) really sucks. Let say we were using a crappy kit zoom lens with an MTF of 0.3. With the old camera; 0.3 X 0.7 =.21. Let’s spend a fortune on the newer, better camera, and we get 0.3 X 0.9 = 0.27. So our overall system MTF only went up a bit (0.07) because the lens really sucked. But if it had been just an average lens or a better lens (let say the MTF was 0.6 or 0.8), we’d have gotten a pretty similar improvement.

If you have a reasonably good lens and/or a reasonably good camera, upgrading either one upgrades your images. If you ask something like ‘is my camera going to out resolve this lens’ you sound silly.

Roger’s rule: If you have either a crappy lens or crappy camera, improve the crappy part first; you get more bang for your $. I just saw a thread for someone wanting to upgrade to the newest 60-megapixel camera, and all of his lenses were average zooms. I got nauseous.

[From Roger Cicala, as linked above]
 

 

Jeff

[Olaf_ZG]

The above I do understand, but do apo lenses have more impact on non- monochrom cameras or not? Is apo relevant for monochrom?

[Jeff S]

6 minutes ago, Olaf_ZG said:

Boy, too many Olaf’s here. Thank you for feedback.

His name starts with zero, one.

Jeff

[Jeff S]

2 minutes ago, Olaf_ZG said:

The above I do understand, but do apo lenses have more impact on non- monochrom cameras or not? Is apo relevant for monochrom?

A better lens improves the system. An APO lens is typically a better lens.

Jeff

[RexGig0]

When I was interested in adding a Noctilux 50mm, in early 2022, with the specific goal of letting more light enter my M Type 246 Monochrom camera, rather than upgrade to an M10 Monochrom, I found at least one source that indicated that a particular version left blue light less-well-corrected, which had a specific effect that was/is desirable when shooting black-and-white. I will try to find where I saw/read/heard this.

Edited July 1, 2023 by RexGig0

[01af]

vor 23 Stunden schrieb Olaf_ZG:

... apo lenses are irrelevant to monochrome cameras regarding the apo part. Is this correct? 

Not, it isn't. Because even if the pictures were monochrom, the subjects (and their image thrown on the sensor) aren't.

[RexGig0]

2 hours ago, RexGig0 said:

When I was interested in adding a Noctilux 50mm, in early 2022, with the specific goal of letting more light enter my M Type 246 Monochrom camera, rather than upgrade to an M10 Monochrom, I found at least one source that indicated that a particular version left blue light less-well-corrected, which had a specific effect that was/is desirable when shooting black-and-white. I will try to find where I saw/read/heard this.

OK, I found this video presentation. The coverage of the f/1 Noctilux lenses starts about 20 to 21 minutes into the presentation, and David Farkas discusses this topic. To be clear, the Noctilux lens being discussed does not not have “APO” in its title. The point is that a lens that was intentionally designed to be imperfectly-corrected, optically, can be more desirable for black-and-white shooting.

 

Edited July 1, 2023 by RexGig0

[Jeff S]

There’s often a difference between “better performance” (objectively as Cicala describes) and “more desirable rendering” (subjective user-based determination). 
 

Jeff

[Chaemono]

Am 30.6.2023 um 15:05 schrieb Olaf_ZG:

I read somewhere, here on LUF, that apo-lenses are irrelevant to monochrom cameras regarding the apo part. Is this correct? 

I prefer the Summilux-M 50 ASPH II over the APO on the M11 Monochrom. It's super sharp wide open except in the extreme corners and it renders nicer. 

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Hallo,

Look here: Leica M

[IkarusJohn]

7 hours ago, Jeff S said:

A better lens improves the system. An APO lens is typically a better lens.

Jeff

There we go.