Current 50 Summilux due for an update?

[lct]

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DOF at f/1.4 is very shallow, in fact 1.5cm at minimum distance of 0.7m. The quite significant field curvature of the Summilux 50mm thus results in a certain loss of sharpness around the object (blur), which is recognized as object sepration ("pop"). [...]

 

That's what i noticed as well but i did not know that "glow" can be associated with field curvature as you suggest it. To me, glow is a sort of halo around highlights one can see out of lenses like 35/1.4 pre-asph at full aperture but i may be wrong.

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[Jeff S]

The Summilux 50mm is a modern optical design with very good performance. Stopped down, it is sharp and aberrations are well controlled. Field curvature at f/1.4 is even appreciated (producing the "glow").

 

Of course, newer calculations allow for even better control. Good examples are the APO Summicron 50mm f/2 or the Voigtländer APO Macro Lanthar 65mm f/2 (E mount). However, the required effort at f/1.4 is far greater than it is at f/2, resulting in quite a number of elements and groups, usage of XA and ED glass, etc. In the end, the lenses become very large, bulky and especially heavy. The incorporation of asperical elements into fast lenses also caused a lot of CA with digital sensors (which unofrtunately plagues the Summiluxes like the 28mm or 21mm) and the bokeh deteriorated in addition.

 

Fast update cycles of other manufactures are a race for optimal image quality, fast autofocus, reduced production cost - and especially marketing to keep sales up.

 

I am convinced there will be an update of the Summilux 50mm at some point of time. The new lens will be better in terms of otpical performance and it will be more expensive. But Leica has also always kept their lenses smaller and lighter than the competitor's offers - and that is the biggest challenge in my opinion. The M lives from being small, light and portable.

I hope you read the Karbe interview I linked. He describes the specific challenges designing the 50 Summilux ASPH M, including aberrations, contrast, field curvature, size etc, especially including the special glass required (one element cost more than all the glass in the prior version).

 

Jeff

Edited November 23, 2017 by Jeff S

[pgk]

That's what i noticed as well but i did not know that "glow" can be associated with field curvature as you suggest it. To me, glow is a sort of halo around highlights one can see out of lenses like 35/1.4 pre-asph at full aperture but i may be wrong.

 

Field curvature does not produce 'glow' nor 'pop'. Field curvature simply means that the plane of focus isn't planar but curved. Its something that underwater photographers like myself curse because its an inherent problem with spherical lens ports and believe me, its doesn't have any pleasant side effects like 'glow' or 'pop'. Anything termed 'glow' or 'pop' is usually on a 'small scale' and is associated with significant and fairly abrupt tonal shifts which then exhibit spurious lightening on their darker side. It usually results from uncorrected aberrations as in the non-aspherical 35mm Summilux.

[lct]

Yes but the feeling of "pop" can come from the fact that subject matters which should be sharper are actually blurred due to field curvature don't you think so?

[mls1483]

There are no scientific definitions of "pop" and "glow" I know of.

 

With "pop" people just refer to a certain 3D look, which means the subject "pops" out of the plane.

 

The notorious Leica "glow" is just a certain rendering. To my believe this glow is (at least partially) due to imperfect correction of certain aberrations. But colors, contrast, bokeh, etc may certainly also contribute. 

[mls1483]

I hope you read the Karbe interview I linked. He describes the specific challenges designing the 50 Summilux ASPH M, including aberrations, contrast, field curvature, size etc, especially including the special glass required (one element cost more than all the glass in the prior version).

 

Jeff

 

 

Missed that, thank you. There ist also an interesting interview with him about the 50mm APO Summicron:

 

http://www.overgaard.dk/leica-50mm-APO-Summicron-M-ASPH-f-20.html

[pgk]

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Yes but the feeling of "pop" can come from the fact that subject matters which should be sharper are actually blurred due to field curvature don't you think so?

 

No. Field curvature is usually across the frame . Any feeling of 'pop' would need a subject to be such that the resultant softening towards the corners interacted appropriately with the subject's planar or even 'concave towards the camera's' characteristics, the aperture used and also emphasised the out of focus areas. Its possible I suppose, but from my observations would need a rather rare set of circumstances and even then would need specific viewing to make it work. I would very much doubt that you would get such 'pop' from the 50mm Summilux Aspheric simply because field curvature is relatively low and well corrected. More likely on the pre-aspheric lens IMO but still not very likely.

 

The problem with such terms is that they are ill-defined and subjective but in this discussion I'm taking 'pop' to roughly to mean 'emphasised more than expected'. Unless someone is going to carefully define and post a relevant sample that is .

[wattsy]

Perhaps ask Pop what he thinks?

[pop]

[hoppyman]

Then you could be sending it in for a very loose aperture ring (both samples I tested). And the compact design sacrifices the fully knurled focus ring, and places it tight against the aperture ring. I loved it optically when I rented it, but preferred my Summilux ASPH ergonomically.

 

There will be a limited edition 50 APO LHSA version, which might address my concerns, but it sacrifices the nifty built-in hood and will likely cost near $10k.

 

State of the art doesn't mean perfect or issue free.

 

Jeff

Have only seen one once and briefly. My comment based on reported optical excellence and my own preference to not need f /1.4. Note I mentioned...if I had the budget anyway. But my M system is virtually unused these days in any case. I was mainly trying to contribute my actual experience with the Summilux over the 10 years or so that I used mine.

[Jeff S]

Have only seen one once and briefly. My comment based on reported optical excellence and my own preference to not need f /1.4. Note I mentioned...if I had the budget anyway. But my M system is virtually unused these days in any case. I was mainly trying to contribute my actual experience with the Summilux over the 10 years or so that I used mine.

Same here. I've had mine for many years and enjoy it, although my preference is generally for Summicrons. My point was a hypothetical one for you, I.e., the APO is no more immune from service issues than your Summilux, state of the art or not.

 

Jeff

[darylgo]

The OP has asked a question that is relevant today with rapid technology advancements, thanks OP.  Leica's philosophy is different than many manufacturers including Zeiss.  Prior to digital 35mm lenses did not need the resolution that has all the Japanese manufacturers in a race to replace their just-good-enough-for-film lenses with their new digital releases.  Leica otoh had a philosophy of making the best lenses possible and have held up well to the rapid digital resolution onslaught.  It's only in the last few years that others are able to achieve what Leica has been producing for decades, however nobody can approach Leica in size and build quality.   If perfection or getting as close as possible is the ultimate goal of lens manufacturing then the 50 apo has achieved this in a diminutive size, maybe Leica is working on a new summilux but to what end.  

 

As for glow, its elusive, perhaps, just maybe, the lenses best to achieve this are the early lenses with mtf curves that dip very low, touching zero or slightly above.  So, the mix could be field curvature along with low contrast.  

Edited November 24, 2017 by darylgo

[pgk]

.....  but to what end. 

 

Isa very pertinent question. The assumption that image 'quality', however it is defined, will increase as technology progresses is odd. Few stop to ask why this should be and how relevant would it be anyway. My view is that the Apo-Summicron is a statement lens rather than a lens which actually delivers 'better' photographs, and I've seen nothing to dissuade me of this opinion. It seems to be a shame that many can't just enjoy shooting a Leica rangefinder with M lenses and accept that the combination is great to use and produces stunningly good image quality as it is. Much more is down to the person behind the camera than a nuance better lens.

[hoppyman]

Same here. I've had mine for many years and enjoy it, although my preference is generally for Summicrons. My point was a hypothetical one for you, I.e., the APO is no more immune from service issues than your Summilux, state of the art or not.

 

Jeff

Yep understand what you are saying. Perhaps more clearly I can express that, when needing service (once because I dropped it and my M), reportedly my Summilux 50 needed to be virtually rebuilt in Germany. That was perhaps due to the nature of the design and construction. By comparison my current Summilux 35. when it needed a back focus adjustment (under warranty) was serviced very quickly by the official repair agency in my country. They are unable to perform any servicing on the 50.

So my speculation that the more recent designs have less complex or at least more amenable designs for service.

 

[Jeff S]

Yep understand what you are saying. Perhaps more clearly I can express that, when needing service (once because I dropped it and my M), reportedly my Summilux 50 needed to be virtually rebuilt in Germany. That was perhaps due to the nature of the design and construction. By comparison my current Summilux 35. when it needed a back focus adjustment (under warranty) was serviced very quickly by the official repair agency in my country. They are unable to perform any servicing on the 50.

So my speculation that the more recent designs have less complex or at least more amenable designs for service.

 

Maybe the special glass in the 50 (Karbe interview I linked) was affected by the drop. In any case, adjusting for back focus is not generally a complicated affair.

 

Jeff

[hoppyman]

I don't think that's relevant Jeff. The first two servicings (loose focus ring operation and then back focus) predate the drop. (2009, 2012, 2013)

[Jeff S]

But I can't imagine that either of those issues prompted a rebuild; that had to result from something more problematic. Anyway, that's history.

 

Jeff

[klinerm]

The OP had a great question, but I want to reassure him also.

 

I have 50 Lux asph, Noct 0.95, 50 apo asph, 50 cron, Zeiss Zm 1.5 - they all render differently, they all are delightlul, I use each and enjoy each very much. But the 50 Lux asph may be the best of the bunch. When I look at images using it on my M9, it is more like looking through a window to a moment in the past, than looking at a digital image. It is a gem. Buy it. It may easily be the best lens for 35 mm frame in existence, let alone the best 50.

 

Richard

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Hallo,

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[darylgo]

It is a gem. Buy it. It may easily be the best lens for 35 mm frame in existence...

 

Richard

Well said.  +1

[pico]

As for glow, its elusive, perhaps, just maybe, the lenses best to achieve this are the early lenses with mtf curves that dip very low, touching zero or slightly above.  So, the mix could be field curvature along with low contrast.  

 

Film of the era is largely responsible for the so-called 'glow'.