Re: M-mount lenses: Which ones perform well on Leica and Sony?
nehemiahphoto wrote: retrofocus wrote: Steve Spencer wrote: retrofocus wrote: Fred Miranda wrote:
Based on the above performance on both Sony and Leica cameras, it'd say the Voigtlander 75/1.5 Nokton performs similarly on both systems. At first when I wrote my Voigtlander 75/1.5 Nokton review, I had assumed the weaker mid-field performance wide open was due to Sony's thicker sensor stack but it's just not the case. It seems to be a characteristic of this lens.
So, for those Sony shooters who are waiting for the CV 75/1.5 E-mount, the current M-mount should be just as good.
So far confirms the rule of thumb with M lenses on Sony MLCs that at focal lengths with 35 mm and above plus wider open rear lens (apertures f/2 and wider open) work well on unmodified Sony sensors with thicker stack. It's only with wider lenses (and/or smaller rear lens element) where the angle of refraction is steeper especially towards the borders/corners of the FF sensor that some unsharpness and color fringing can occur.
I would characterize the rule of thumb slightly differently. In particular a lot of 35mm lenses perform poorly on Sony cameras with the thicker sensor stack. The Leica M 35 f/2 Asph for example is one of the lenses most affected by the thick sensor stack and the Leica 35 f/1.4 Asph is noticeably affected as is the Zeiss ZM 35 f/1.4. Even the Voigtlander 35 f/1.7 is quite affected.
So, I would say as a rule of thumb that wider than 50mm most lenses are affected by the thicker sensor stack and even 50mm lenses are mildly affected. Longer than 50mm, however, lenses tend to be only mildly affected. One of the crucial variables in whether a lens is affected by the sensor stack thickness is the exit pupil of the lens. Lenses with shorter exit pupils will be more affected, and longer lenses tend to have longer exit pupils. Most 35mm lenses have pretty short exit pupils too.
I should have added into the exemption of poor performing wider lenses ASPH f/2 lenses - you are absolutely right, and I have described the same with the Leica 35/2 ASPH in the past in this forum. On the other hand, the Leica 35/1.4 ASPH does very well with the Sony sensor stack - which comes back to my point with the larger rear lens element.
Btw, I find the often in this forum used term "exit pupil" very confusing. Not sure if the majority understands what exactly it means in this context. Is it the same as what I was saying that the angle of refraction is steeper towards the border of the sensor frame with smaller rear lens elements?
Do you have crops/a link to show that the 35 Lux ASPH does better? I was under the impression it doesn't, and before I sold my ASPH pre-FLE I did some light testing and it really didn't do well till pretty stopped down across most the frame (at infinite at least). I have toyed with the idea of getting the lens a couple times since letting it go...
I still had one photo which I took with the Leica 35/1.4 Lux lens back in 2014 when I tested this lens inside a Leica store on my A7R. Not exactly sure which aperture I selected, but the photo has quite shallow DoF. The corners turned out all fine, and there is no focus shift towards the center which is the case with the 35/2.0 ASPH.
I didn't buy the 35/1.4 lens back then and bought instead later a mint copy of the older 35/2.0 vers. IV lens (no ASPH!) which I love using both on film and digital.
Re: M-mount lenses: Which ones perform well on Leica and Sony?
nehemiahphoto wrote: retrofocus wrote: Steve Spencer wrote: retrofocus wrote: Fred Miranda wrote:
Based on the above performance on both Sony and Leica cameras, it'd say the Voigtlander 75/1.5 Nokton performs similarly on both systems. At first when I wrote my Voigtlander 75/1.5 Nokton review, I had assumed the weaker mid-field performance wide open was due to Sony's thicker sensor stack but it's just not the case. It seems to be a characteristic of this lens.
So, for those Sony shooters who are waiting for the CV 75/1.5 E-mount, the current M-mount should be just as good.
So far confirms the rule of thumb with M lenses on Sony MLCs that at focal lengths with 35 mm and above plus wider open rear lens (apertures f/2 and wider open) work well on unmodified Sony sensors with thicker stack. It's only with wider lenses (and/or smaller rear lens element) where the angle of refraction is steeper especially towards the borders/corners of the FF sensor that some unsharpness and color fringing can occur.
I would characterize the rule of thumb slightly differently. In particular a lot of 35mm lenses perform poorly on Sony cameras with the thicker sensor stack. The Leica M 35 f/2 Asph for example is one of the lenses most affected by the thick sensor stack and the Leica 35 f/1.4 Asph is noticeably affected as is the Zeiss ZM 35 f/1.4. Even the Voigtlander 35 f/1.7 is quite affected.
So, I would say as a rule of thumb that wider than 50mm most lenses are affected by the thicker sensor stack and even 50mm lenses are mildly affected. Longer than 50mm, however, lenses tend to be only mildly affected. One of the crucial variables in whether a lens is affected by the sensor stack thickness is the exit pupil of the lens. Lenses with shorter exit pupils will be more affected, and longer lenses tend to have longer exit pupils. Most 35mm lenses have pretty short exit pupils too.
I should have added into the exemption of poor performing wider lenses ASPH f/2 lenses - you are absolutely right, and I have described the same with the Leica 35/2 ASPH in the past in this forum. On the other hand, the Leica 35/1.4 ASPH does very well with the Sony sensor stack - which comes back to my point with the larger rear lens element.
Btw, I find the often in this forum used term "exit pupil" very confusing. Not sure if the majority understands what exactly it means in this context. Is it the same as what I was saying that the angle of refraction is steeper towards the border of the sensor frame with smaller rear lens elements?
Do you have crops/a link to show that the 35 Lux ASPH does better? I was under the impression it doesn't, and before I sold my ASPH pre-FLE I did some light testing and it really didn't do well till pretty stopped down across most the frame (at infinite at least). I have toyed with the idea of getting the lens a couple times since letting it go...
I still had one photo which I took with the Leica 35/1.4 Lux lens back in 2014 when I tested this lens inside a Leica store on my A7R. Not exactly sure which aperture I selected, but the photo has quite shallow DoF. The corners turned out all fine, and there is no focus shift towards the center which is the case with the 35/2.0 ASPH.
May 28, 2020 at 06:45 AM
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