The special character of Leica‘s APO lenses

[Jan1985]

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I just want to ask you guys what is special about Leica‘s APO lenses and their style of rendering? Is there some kind of „character“ in your oppinion? What does it make so appealing and are they able to make an image „better“ compared to a non-APO lens?

[jaeger]

I used to own a 90 APO, it supposed to render less CA, it was pretty sharp but no special characters I have ever noticed.

[frame-it]

54 minutes ago, Jan1985 said:

I just want to ask you guys what is special about Leica‘s APO lenses and their style of rendering? Is there some kind of „character“ in your oppinion? What does it make so appealing and are they able to make an image „better“ compared to a non-APO lens?

you mean No character, just a clean clinical image 🤣

[pippy]

57 minutes ago, Jan1985 said:

I just want to ask you guys what is special about Leica‘s APO lenses and their style of rendering? Is there some kind of „character“ in your oppinion? What does it make so appealing and are they able to make an image „better“ compared to a non-APO lens?

When considering rendering of lenses opinions as to what is meant by "Special", "Character" and "Better" are purely individual concepts. Nothing more nor less.

Make up your own mind.

Philip.

Edited November 2, 2023 by pippy

[AndreasG]

I only can talk about the APO Summicron 2/50, it is sharp and rich of contrast corner to corner, just as a lens should be, nothing else is outstanding compared with a non APO Summicron. Being king of the data sheet does not guarantee a special character in the photos.

[pgk]

The way a lens produces an image is both simple and yet highly complex. Simple because all lenses can produce images. Complex because in order to produce an image which is highly detailed and distortion free requires a high degree in both design and production. The latest high quality lenses from most manufacturers are now quite extraordinarily good but in all honesty lenses have been surprisingly good for a long time inasmuch as they have produced very acceptable images which have been 'fit for purpose' for decades if not longer.

So trying to determine the nuance of enhanced performance is not really about a lens being significantly, or often even noticeably, 'better' but about increasing its measurable precision in technical performance parameters. Whether this is sufficient for their buyers and owners to appreciate and accept the premium price paid for them is up to those individuals. Whether it makes any real difference in real world photography I rather doubt. The only place it might is wide-open on subjects which require high performance at full aperture. In my experience this is a rare situation but others might disagree depending on what they photograph.

[Robert Blanko]

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„Better“ depends on the intended purpose.

I like my APO lenses for their outstanding clarity and neutral rendering in particular for landscape photography.

But for other purposes such as portraits other lenses might be more appealing.

[fil-m]

By "character" most would expect, at least based on my interpretation, some kind of lens specific glow, softness, lower contrast, bokeh transition, distortion and aberrations plus sometimes, the "muted" color profile. The way these characteristics unfold for a given lens and how they are unique to that lens, define its character.

As APO lens have limited glow, are rather sharp, with high contrast, little aberrations and a very sharp bokeh fall off, they are unfairly considered (in my view) as lacking character. Maybe because they barely alter the image with very little "contamination" or alteration.

That being said, I like the challenge that each lens gives. With my APO-M lenses I love the challenge of focusing on composition as well as image content. Subject separation becomes my main artistic choice, the lens does not add (or subtract) much on its own. In addition, the black and white rendering of APO lens is lovely (again it is subjective), giving this kind of "wet" look to images often described by other members of the forum due to the high contrast and strong micro contrast. With high ISO noise, it becomes also more interesting

Thus I don't see APO images as necessarily better (or worse), just different with their own signature. My old noctilux or the summilux 35 reissue will give their "mood" to the image, which is nice. My APO lens gives less "mood" but make the subject (or the composition) standout - at least if/when there is an interesting subject and composition. At the end, it is about the photographer, or the lens, ideally both the photographer and the lens working in harmony. So you may choose the lens (APO or non-APO) that fits your purpose and "own mood" in a given context aiming for the kind of photographic rendering and signature that you are seeking. 

[RexGig0]

17 hours ago, Jan1985 said:

I just want to ask you guys what is special about Leica‘s APO lenses and their style of rendering? Is there some kind of „character“ in your oppinion? What does it make so appealing and are they able to make an image „better“ compared to a non-APO lens?

An APO can be described as having less “character” than a non-APO lens, because optical aberrations are the source of much of what some folks describe as “character.” I would not want all of my lenses to be APO. I like different “character,” or different visual signatures, for different goals, and loathe sitting at a computer, to process significant changes in my images. 

Let us keep in mind that “APO” is a marketing term. An apochromatic lens is corrected for specific color wavelength aberrations, and some APO lenses are more-corrected than others. One well-known lens, that lacks an APO suffix, the Summilux-M 50mm ASPH, has been acknowledged by the leader of the design team, Peter Karbe, to be an APO lens. My take is that this Summilux was, quite simply, designed and introduced before APO was used as a marketing term by Leica. Perhaps, a future Summilux-M 50mm ASPH will have increased apochromatic correction, and be labeled with an APO suffix.

I am glad to have some vintage lenses, and some of the “heritage” or “re-edition” lenses, as well as some APO lenses. Life is good. 🙂

I am not any kind of expert.

Edited November 3, 2023 by RexGig0

[adan]

My observation (from trying, but not owning, multiple "APO" Leica-made M lenses) is that the common factor across most of them is extremely crisp resolution wide-open, in the plane of focus - while at the same time producing very smooth bokeh in the blurry areas. And usually "more" bokeh - larger blurs at a given aperture, as well as softer, and and with a rapid fall-off in resolution away from the plane of best focus.

Which historically have been mutually exclusive features. Older lenses with great bokeh almost always "achieved" that (not always by intent) by undercorrecting spherical aberration, which degraded wide-open resolution (e.g. 75 Summilux-M - 1980). While lenses with really good correction of SA (e.g. regular 50mm Summicron v4/5, 35mm Summicron v.4, also 1980) produce a lot of hard-edged "bright-ring/'bubble'/busy" bokeh.

(I know, I know - that means somewhat different apparent DoF from two lenses at the same aperture setting, which isn't supposed to happen. But DoF is calculated for an "ideal" lens. Which does not exist. But the APO lenses get closer to the "ideal").

To illustrate what I mean, my famous comparison of the 75 Summilux (top) and 75 APO-Summicron-M-ASPH, regarding DoF, clarity and bokeh (close-up). The APO-Summicron has narrower DoF (readable area of type). The APO is sharp - or it isn't. The non-APO produces "natural focus-stacking" as the edges and center of its lens elements focus at different distances (SA):

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It should be noted that virtually all APO M lenses are also ASPH lenses, so that effect may be a combination of both APO and ASPH qualities.

It should also be noted that for Leica, in recent years, APO is not quite the same thing as APOchromatic. As RexGig0 points out. Leica has recently said that APO for them means simply "our really, REALLY 'best' lenses." The unlabeled 50 Summilux ASPH fits my description in paragraphs 1/2 as well - but was named when Leica was still using the more traditional meaning of APO(chromatic).

The one APO M lens I do own is the 135 APO-Telyt-M (not ASPH -1998) - the first M APO ever (just ahead of the 90 APO-Summicron-M-ASPH, and excepting some very-limited-production military-contract lenses). It is a classic apochromatic lens - very little CA or SA, extremely sharp, and with a rapid focus fall-off outside the plane of focus. But not the smoothest bokeh ever, in many cases. Its predecessor 180mm APO-Telyt-R (1975) is similar - bokeh was not a "thing" in the 1970s. 😁

Edited November 3, 2023 by adan

[Robert Blanko]

Here is an interesting comparison of the 35 Lux and the 35 APO which ultimately convinced me to buy the APO instead of the Lux :

http://www.lichtknoten.com/webblog/?tag=apo-summicron-m-35-f-2-asph

 

 

[jrp]

APO lenses produce clearer (freer from artefacts images).  The artefacts are amplified on digital cameras (relative to film).  The artefacts (eg, colour fringing) matter less, or not at all, for black and white images.

The likes of the SL Summicrons are APO at all distances.

Does it matter?  Sometimes it does (eg, backlit water spray).  Sometimes the aberrations give some photos an attractive signature.

My simplistic take is that the only people interested in token, etc, are photographers as it’s difficult to have the emotional connection with it that non-photographers find makes a photograph compelling.

[pgk]

4 hours ago, adan said:

Leica has recently said that APO for them means simply "our really, REALLY 'best' lenses."

I have always understood that apochromatic meant that a lens was corrected in order to ensure that three colurs were brought into focus in the same plane. However, as pointed out here: https://en.wikipedia.org/wiki/Apochromat soma manufacturers use the term 'loosley'. It may well be applied to Leica's 'best' lenses but it does have a technical definition which I would hope was fulfilled by Leica's designated lenses. It is worth understanding that lenses with aspheric elements will often (always?) show rings within their spherical bokeh circles as a result so this is one of the trade offs resulting from the use of such elements, and is one reason why they may have a slightly disconcerting character in oof areas under samoe conditions.

[Jeff S]

For those who haven’t read the story, David Farkas (also Leica Miami) was told by Karbe why the 50 Summilux ASPH wasn’t called APO, unlike the similarly constructed 75 Summicron APO.  He thought at the time it would have been “silly” to refer to the 50 as APO.

https://www.reddotforum.com/content/2008/09/photokina-2008-day-2-taking-it-easy-and-getting-an-education-from-peter-karbe/
 

Jeff

[hansvons]

On 11/2/2023 at 9:22 PM, Jan1985 said:

Is there some kind of „character“ in your oppinion?

Yes. Their design creates a short focus roll-off as @adan eloquently described in his post. This is unique to APO lenses and can create quite stunning images in medium long shots/environmental portraits at full aperture. The Summicron 35mm APO SL is a prime example in this sense. And yes, I‘d call it a character lens.

APO 50mm lenses (most modern large and expensive 50mm primes have apochromatic elements) tend to "cut out" the heads in typical portraits due to the short roll-off, which isn‘t exactly what I‘m after. 

 

[evikne]

I must admit that I think the 35mm APO-Summicron-M has a very appealing rendering. I like the very crisp details and the soft, frosted glass-like bokeh. I also like the wide focus ring. If I had the money, I would definitely buy it.

But I probably would have gotten bored with it after a while and gone back to my 60s design lenses, which I never get bored with.

[RexGig0]

I bought my Cosina Voigtlander 50mm APO Lanthar, not necessarily because of any amount apochromatic correction, but because its coatings resist flare, better than the coatings on the optical elements of most Leica lenses, including my Summilux-M 50mm ASPH and APO Summicron-M 75mm ASPH, and, as seen in this you-tube video, better than the Leica APO Summicron-M 50mm ASPH, which I do not (yet) own:

Until I bought the Voigtlander APO Lanthar, if I had to shoot in bad glare conditions, and wanted/needed to prevent veiling flare, I would use a Carl Zeiss Distagon 35mm f/1.4 ZM, with its T* (“T Star”) coatings. Of course, a 35mm lens is not a 50mm or 75mm lens, so, that was occasionally inconvenient. (I could, however, cheat, as necessary, by using a Canon or Nikon DSLR camera and lens. 😉 )

Edited November 4, 2023 by RexGig0

[costa43]

I’ve owned and sold the 35mm Leica APO and still own a Voigtlander APO 50mm that I’ve tried across 4 different digital Leica bodies. Some pics below on the mm1, m10r and M9p 

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Edited November 9, 2023 by costa43

[costa43]

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Hallo,

Look here: Leica M

[costa43]

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