APO Summicron 50/2 ASPH: Central veiling flare / fogging

[wlaidlaw]

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Stephen,

 

Modern lenses can be made very flare resistant. In 50mm lenses both my 0.95 Noctilux and ZM Planar seem to be as resistant as I could reasonably need them to be. I would think that in the circumstances posted on a number of example images from the 50 APO on this thread, the above two lenses would have shown considerably less flare. Given the price of the 50APO, you might hope it would be a “without commercial compromise” lens.

 

There are lenses made where the manufacturer declares that they are special purpose lenses and consequently have limitations. People are advised only to buy such lenses in the full awareness of the limitations (I am thinking of the Zeiss ZM 50/1.5 Sonnar as an example). No such proviso was given for the 50APO, thus any purchaser would be entitled to expect that it would be at least as good as its competitors in all aspects and given the price, better in many. I was thinking of getting the 50APO rather than the Nocti, which I have to admit, I find a bit of a struggle from the weight perspective. I am now very glad I didn’t. Having read a couple of comparative reviews between the 50APO and the 50ZM Planar, I think for my level of abilities, the Planar is more than good enough, with the Noctilux for lower light situations. I have been pleasantly surprised that weight apart, what a good general purpose 50mm lens the Noctilux is.

 

Wilson

[lct]

...People are advised only to buy such lenses in the full awareness of the limitations (I am thinking of the Zeiss ZM 50/1.5 Sonnar as an example)...

Would you mind to point me to such warnings about the ZM 50/1.5? Just curious (Sonnar lover speaking).

[Jeff S]

Would you mind to point me to such warnings about the ZM 50/1.5? Just curious (Sonnar lover speaking).

 

The issue is focus shift for apertures wider than f2.8. See, for instance, the 'Update' section at the bottom of this LuLa page, which has language provided by Zeiss.

 

Jeff

[lct]

Thank you Jeff i did not know this Zeiss message from 2007. The lens is now calibrated for sharp focus at f/1.5 instead of f/2.8, which is written nowhere officially IMHO.

[StephenPatterson]

Stephen,

 

There are lenses made where the manufacturer declares that they are special purpose lenses and consequently have limitations. People are advised only to buy such lenses in the full awareness of the limitations (I am thinking of the Zeiss ZM 50/1.5 Sonnar as an example). No such proviso was given for the 50APO, thus any purchaser would be entitled to expect that it would be at least as good as its competitors in all aspects and given the price, better in many.

Wilson

 

Thanks Wilson, I appreciate your comments. My question, which is all it is, really requires an optical engineer (which I am not) to weigh in as to whether it's even reasonable to speculate that a design which had a decrease in lens coatings could result in an increase in micro contrast, sharpness and resolution (all items stressed by Peter Karbe as key design goals) at the expense of flare suppression for the 50 APO.

 

I think if the problem was blacking of internal components and element edges that Leica would have issued a recall, instead of the current position of "It's not a problem for everyone". Why is it not a problem for everyone? Is there a physical difference in lenses from the first batch, or just a difference in owner's perspective as to which design goals are most important?

 

If only Leica would employ a full time Press Secretary/Spokesperson to address question in an ongoing, official manner we wouldn't have to spend so much time reading the tea leaves.

[wlaidlaw]

Would you mind to point me to such warnings about the ZM 50/1.5? Just curious (Sonnar lover speaking).

 

I am not saying there is anything wrong with the Sonnar (I use an earlier version myself) just that Zeiss designed it to draw in a particular way, that leads to certain limitations, which Jeff has kindly already pointed out for me. I think it was audacious of them to try something different but I suspect it has not been a huge commercial success. I would guess if they had gone for an ASPH Summilux 50mm/f1.4 competitor at a lower price point, it would have sold far more.

 

Wilson

[LocalHero1953]

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Drifting OT, but this thread has meandered a bit anyway.

I bought the ZM Sonnar 50/1.5 for its qualities and knowing its limitations. Others know lens history better than me, but I understand it is essentially the original Zeiss Sonnar design from 60+ years ago, but brought up to date with modern coatings. They seem to have done the same with the ZM Sonnar 85/2, but that was discontinued a couple of years ago. Others have done the same: I think the CV Heliar 75/1.8 is a similar updated, coated version of the old Leitz Hektor 73/1.9. An interesting area to explore!

[algrove]

Stephen,

 

Modern lenses can be made very flare resistant. In 50mm lenses both my 0.95 Noctilux and ZM Planar seem to be as resistant as I could reasonably need them to be. I would think that in the circumstances posted on a number of example images from the 50 APO on this thread, the above two lenses would have shown considerably less flare. Given the price of the 50APO, you might hope it would be a “without commercial compromise” lens.

 

There are lenses made where the manufacturer declares that they are special purpose lenses and consequently have limitations. People are advised only to buy such lenses in the full awareness of the limitations (I am thinking of the Zeiss ZM 50/1.5 Sonnar as an example). No such proviso was given for the 50APO, thus any purchaser would be entitled to expect that it would be at least as good as its competitors in all aspects and given the price, better in many. I was thinking of getting the 50APO rather than the Nocti, which I have to admit, I find a bit of a struggle from the weight perspective. I am now very glad I didn’t. Having read a couple of comparative reviews between the 50APO and the 50ZM Planar, I think for my level of abilities, the Planar is more than good enough, with the Noctilux for lower light situations. I have been pleasantly surprised that weight apart, what a good general purpose 50mm lens the Noctilux is.

 

Wilson

 

You know Wilson, your post has me thinking of taking to Europe this summer just 3 E60 lenses--21/2.8, 50/0.95 and 75/1.4. Got my Variograu now so no limitations.

[wlaidlaw]

You know Wilson, your post has me thinking of taking to Europe this summer just 3 E60 lenses--21/2.8, 50/0.95 and 75/1.4. Got my Variograu now so no limitations.

 

Lou,

 

Of course, the 80-200/f4 is E60 as well .

 

I was using the same Heliopan slimline polaroid filter on both it and the Nocti.

 

Wilson

[algrove]

Lou,

 

Of course, the 80-200/f4 is E60 as well .

 

I was using the same Heliopan slimline polaroid filter on both it and the Nocti.

 

Wilson

 

Thanks for the reminder. I sent my last 80-200 to Leica for rubber replacement. Common issue I hear. I will keep this one as it one of the last 100 made.

[dewilde]

Thanks Wilson, I appreciate your comments. My question, which is all it is, really requires an optical engineer (which I am not) to weigh in as to whether it's even reasonable to speculate that a design which had a decrease in lens coatings could result in an increase in micro contrast, sharpness and resolution (all items stressed by Peter Karbe as key design goals) at the expense of flare suppression for the 50 APO.

 

I think if the problem was blacking of internal components and element edges that Leica would have issued a recall, instead of the current position of "It's not a problem for everyone". Why is it not a problem for everyone? Is there a physical difference in lenses from the first batch, or just a difference in owner's perspective as to which design goals are most important?

 

If only Leica would employ a full time Press Secretary/Spokesperson to address question in an ongoing, official manner we wouldn't have to spend so much time reading the tea leaves.

 

 

Interesting you say that. My first lens was all that; micro-contrast, macro-contrast, sharp, vibrant etc, very Zeiss like pop, but very Leica like rendering, and since I'm a fan of both companies, this lens was awesome. But there was so much flare of all types that the lens was unusable in a large majority of the situations I was in. More so then any of the other 50mm lenses I own (50Noct, 50lux-asph, 50sonnar, 50planar, 50MPZE, 501.4G, 50L, 50ZA, 55FE, 80/2contax645, or have owned, but that list would be to long)

 

Sent it in, fixed it, came back I guess overcoated? It was muddy, lacked contrast and sharpness and vibrancy. All but one ring was blackened.

 

Sent it in again, now much more contrasty and a bit more vibrant, but not what it was the first time around, although flare is a bit better managed, so is CVF, although I've noticed more issues with it now (weird orbs show up in my shots perfectly round, not CVF style, more like corner style and just like tinted orbs). But to note, my rings are back to being non-blackened..

 

So I'm going to assume that "blackening" the rings wasn't really the issue, and that it's coating strength. Although I'm not an engineer.

 

 

Think what I'll do is use the lens for a year, as I like the rendering, and then when more of you start getting your 50APO lenses, and I hear better overall feedback about the lens, I'll send mine in again.

 

Anyway, I'm going to LA where the light is beautiful, so maybe that'll help, since to be fair, I used the lens far more in Australia and New Zealand and LA the first time around, then I did in Singapore where the light is usually of poor quality.

[wlaidlaw]

It sounds to me like a very similar situation to the 35/f.14 Summilux ASPH, where the design’s element grinding, barrel machining and assembly tolerance demands were a major challenge to Leica’s abilities to deliver at the time (or so it was explained to me during a visit to Solms in 2007). The end result was that sample variation on the lens was unacceptable. The lenses ranged from ones like my second chrome one, which I still have, which is brilliant, to the three that Tim Ashley had, which were poor quality paperweights.

 

As we know, the only solution to the ASPH problem was to redesign the lens to become the FLE and even on that, a lot of the earlier ones had horrible problems with edge CA (a friend of mine is now on his second lens after his first had had multiple visits to Solms).

 

I would not be surprised if the 50APO lens had to have a major redesign. On past performance, one might hope that Leica would institute an exchange program but Wetzlar has to be paid for.

 

Wilson

[StephenPatterson]

Slightly OT but I would like to send a personal note of thanks to Dee (platypus) for the classy correspondence and professional manner in the previous posts. We may disagree, and be at opposite ends of the spectrum with regards to this issue, but it's nice to be able to discuss the question without resorting to unsavory tactics and personal attacks.

[furcafe]

Based on the published diagrams, the ZM 50/1.5 Sonnar (also made in limited numbers in Nikon RF version in Japan) is an updated design of the original Sonnar (not identical, but you can easily see the lineage). The ZM 85/2 Sonnar adhered less closely to the original formula (more of an Ernostar, the Sonnar's ancestor) & included a floating element to improve near focus performance.

 

Drifting OT, but this thread has meandered a bit anyway.

I bought the ZM Sonnar 50/1.5 for its qualities and knowing its limitations. Others know lens history better than me, but I understand it is essentially the original Zeiss Sonnar design from 60+ years ago, but brought up to date with modern coatings. They seem to have done the same with the ZM Sonnar 85/2, but that was discontinued a couple of years ago. Others have done the same: I think the CV Heliar 75/1.8 is a similar updated, coated version of the old Leitz Hektor 73/1.9. An interesting area to explore!

[furcafe]

You may be conflating 2 different versions of the pre-FLE 35/1.4 Summilux. The 1st, marked "Aspherical", had 2 hand-ground aspherical elements & was quickly discontinued due to manufacturing difficulties. The 2nd, marked "ASPH.", had a single, molded aspherical element. Sample variation aside, I never heard that Leica had any problems making the 2nd version; the FLE design was intended to improve near focus performance. Then again, perhaps I'm just lucky, as my c.1997 35/1.4 ASPH has been stellar for me (even close up) & I've never been tempted to get the current FLE.

 

It sounds to me like a very similar situation to the 35/f.14 Summilux ASPH, where the design’s element grinding, barrel machining and assembly tolerance demands were a major challenge to Leica’s abilities to deliver at the time (or so it was explained to me during a visit to Solms in 2007). The end result was that sample variation on the lens was unacceptable. The lenses ranged from ones like my second chrome one, which I still have, which is brilliant, to the three that Tim Ashley had, which were poor quality paperweights.

 

 

Wilson

[wlaidlaw]

I use an older Opton 50/f1.5 Sonnar. Its micro-contrast must be lower than I thought, as it will not trigger focus peaking until around f5.6 and is quite prone to flare. Mind you, a thorough clean and service might help a lot. My 40mm Summicron-C triggers focus peaking a lot better after its clean and rebuild by Malcolm Taylor and also is a lot less prone to flare and veiling glare. The main problem with the older Sonnars (mine is around 1955) is curvature of the focus field. I gather the ZM version is much better in this aspect.

 

To get back to the original topic, do owners of the APO50 feel that the current problems outweigh its advantages? If the problems prove to be incurable, would they wish Leica to refund them, offer a partial refund + exchange for an ASPH Summilux or old type Summicron or take a discounted additional payment in exchange for a Noctilux?

 

Wilson

[wlaidlaw]

You may be conflating 2 different versions of the pre-FLE 35/1.4 Summilux. The 1st, marked "Aspherical", had 2 hand-ground aspherical elements & was quickly discontinued due to manufacturing difficulties. The 2nd, marked "ASPH.", had a single, molded aspherical element. Sample variation aside, I never heard that Leica had any problems making the 2nd version; the FLE design was intended to improve near focus performance. Then again, perhaps I'm just lucky, as my c.1997 35/1.4 ASPH has been stellar for me (even close up) & I've never been tempted to get the current FLE.

 

I am wholly familiar with the difference between the rare “Aspherical” and commoner ASPH 35mm f1.4 Summiluxes. As you have been a member of this forum since 2006, I am sure you must remember the bitter complaints from 35 ASPH Summilux owners when trying to use them on the M8, with lenses aperture shifting totally outside of the DOF. My first one (a black/alloy one) was terrible. It had a small amount of static back focus wide open and had very soft corners. Its aperture shift made it unusable on digital. I sent it back to the dealer within the refund period and let it become someone else’s problem. A few weeks later, I bought a chrome one, again on a sale or return basis, not expecting much. I was amazed to find it was an excellent performer. I left it at Solms to be coded (it was a September 2006 lens, just prior to coding and from the final batch of chrome lenses), with strict instructions that other than changing the mount to a coded one, not to touch anything.

 

BTW although the ASPH element on this lens is made from a moulded blank (like all Leica’s other lens elements) and I believe came from Schott Glass, it is ground on the same computer controlled aspherical band grinders that Leica would have used for the two elements of the Aspherical lens. This machine only finish grinds and therefore must be used on moulded blanks. If you go round Leica, you will see polystyrene trays of the lens element blanks waiting to be ground on either the spherical or aspherical grinding machines.

 

Wilson

[algrove]

I use an older Opton 50/f1.5 Sonnar. Its micro-contrast must be lower than I thought, as it will not trigger focus peaking until around f5.6 and is quite prone to flare. Mind you, a thorough clean and service might help a lot. My 40mm Summicron-C triggers focus peaking a lot better after its clean and rebuild by Malcolm Taylor and also is a lot less prone to flare and veiling glare. The main problem with the older Sonnars (mine is around 1955) is curvature of the focus field. I gather the ZM version is much better in this aspect.

 

To get back to the original topic, do owners of the APO50 feel that the current problems outweigh its advantages? If the problems prove to be incurable, would they wish Leica to refund them, offer a partial refund + exchange for an ASPH Summilux or old type Summicron or take a discounted additional payment in exchange for a Noctilux?

 

Wilson

 

Too early for me to say about my #2, but if I already own the 50lux and 50 Noctilux and do not want the APO50, I would ask for funds back. You would not believe what just arrived from Leica NJ while I am typing this. My lens #1 replacement--more later.

[B-A-C]

Too early for me to say about my #2, but if I already own the 50lux and 50 Noctilux and do not want the APO50, I would ask for funds back. You would not believe what just arrived from Leica NJ while I am typing this. My lens #1 replacement--more later.

 

Al - if you had to choose one lens between the APO 50 and 50 Lux 1.4 asph as an all rounder, which one would you choose?

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Hallo,

Look here: Leica M

[helged]

My lens #1 replacement--more later.

 

Waiting...