M 240: Zeiss C-Biogon 35/2.8 & Leica 35/2 ASPH sample images

[bobby_novatron]

Preamble:
1. I apologize to the mods if this thread is in the wrong forum, but I thought this forum is OK since I used a M 240 as the rangefinder test body.
2. I know the idea of "Zeiss C-Biogon vs Leica 35/2 ASPH" is a concept that has been already discussed by many enthusiasts, but I just wanted to share my recent findings.

Hypothesis:
If I shoot the same scene using the same camera with these lenses, the Leica 35/2 ASPH should out-perform the Zeiss C-Biogon at the same settings. By 'out-perform', I mean less distortion, less chromatic aberration (CA), more detail.

Assumptions:
1. The Leica 35/2 ASPH costs considerably more than the Zeiss, so the added cost should mean the Leica has a 'better' optical formula.
2. The Zeiss C-Biogon will have higher contrast (Zeiss rangefinder lenses have been noted to have more contrast than other brands).
3. The Zeiss should not resolve as well as the Leica, due to the lack of an aspherical element and a different design.

Test Parameters:
1. A Leica M 240 with latest firmware was used as the test body. In-camera JPEG setting at was at maximum resolution (24MP), other parameters at STANDARD.
2. Lens detection was set at AUTO for the Leica product, then set at MANUAL for the Zeiss product. The Leica Summicron-M 35/2 (non-asph) profile was selected for the Zeiss.
3. To simplify things I only took a couple photos of the scene. The sample shots below were set with these parameters:
a. ISO 400, AUTO white balance
b. Lens set at F5.6
c. Focus was set near-infinity, live-view was used to focus on the distant fence-posts.

Note: the images below were resized for the web from the original 24MP files. No post-processing except for re-sizing. Crops are 100% magnification from the top left-hand corner.

#1. Leica Summicron-M 35mm F2 ASPH

#2. Zeiss C-Biogon 35mm F2.8

3. TOP LEFT-HAND CROP, 100%: Leica 35/2 ASPH

4. TOP LEFT-HAND CROP, 100%: ZEISS C-BIOGON

CONCLUSIONS:

1. Money Can't Buy You Love

Despite the magnificent build-quality and Tiffany-like price of the Leica Summicron 35/2 ASPH, the Leica (ahem) has, shall we say, optical challenges in the corners.

This came as a major surprise to me.

I was especially concerned because the images was shot using the M 240 with the correct AUTO lens profile. AFAIK the camera was supposed to take care of CA and other problems, no? Perhaps someone can correct me on this. Otherwise, what is the purpose of having lens profiles?

2. Here Comes The Sun

Yes, I know that the expectations of these lenses are high. Shooting into the late afternoon sun with high-contrast zones would be a challenge for any lens.

But I did not expect the $800 Zeiss to beat the $3000 Leica.

3. Let It Be

Subjectively, an argument can be made that the Leica STILL does an overall better job than the Zeiss.

The Leica's 'micro-contrast' and detail both seem to be subtly better. There is more dynamic range with the Leica, more gradation. Colors are more natural, and the bold contrast of the Zeiss is absent.

---

That's it! Thanks for looking at my non-scientific test of these 2 wonderful lenses. Any shared experiences and thoughts would be appreciated.

 

[rscheffler]

FWIW, Leica's in-camera lens correction is strictly for edge colour shift and vignetting. It does not adjust for other optical defects such as CA or distortion.

My experience with several of the ZM lenses is that they're generally very well corrected for CA, whereas all of my Leica M lenses exhibit some. The ZM21/2.8 seems to have none in normal situations. The 35C is very good with backlighting and with specular light sources in the frame. It's very difficult to make it flare (the ZM21/2.8 flares more easily). It also has quite smooth background rendering at nearer subject distances.

IMO, based on the Leica and Zeiss lenses I own, in general, the Leica have a more subtle, rich rendering whereas the Zeiss are bolder. The Leica have their share of aberrations and therefore are not perfect (contrary to internet hype), but IMO, the balance of aberrations relative to sharpness and contrast results in very pleasing rendering.

An appealing aspect of the 35 Cron ASPH is certainly its very small size for an f/2 lens, which likely results in optical compromises. Also consider it was released in 1997... almost 20 years later and I'm sure Leica could improve it. I'm not much of a 35mm shooter, so never warmed up to the ASPH and have little experience with other options. But I did pick up the Canon 35/2 LTM and it's also tiny. Smaller than the ZM35C, though needs about f/5.6 to be competitive with modern lenses and will never quite match in respect to contrast, saturation or handling of flare.

 

[bobby_novatron]

FWIW, Leica's in-camera lens correction is strictly for edge colour shift and vignetting. It does not adjust for other optical defects such as CA or distortion.

My experience with several of the ZM lenses is that they're generally very well corrected for CA, whereas all of my Leica M lenses exhibit some. The ZM21/2.8 seems to have none in normal situations. The 35C is very good with backlighting and with specular light sources in the frame. It's very difficult to make it flare (the ZM21/2.8 flares more easily). It also has quite smooth background rendering at nearer subject distances.

IMO, based on the Leica and Zeiss lenses I own, in general, the Leica have a more subtle, rich rendering whereas the Zeiss are bolder. The Leica have their share of aberrations and therefore are not perfect (contrary to internet hype), but IMO, the balance of aberrations relative to sharpness and contrast results in very pleasing rendering.

An appealing aspect of the 35 Cron ASPH is certainly its very small size for an f/2 lens, which likely results in optical compromises. Also consider it was released in 1997... almost 20 years later and I'm sure Leica could improve it. I'm not much of a 35mm shooter, so never warmed up to the ASPH and have little experience with other options. But I did pick up the Canon 35/2 LTM and it's also tiny. Smaller than the ZM35C, though needs about f/5.6 to be competitive with modern lenses and will never quite match in respect to contrast, saturation or handling of flare.

Thanks for your input about these lenses. I agree with you 100%. The 35/2 ASPH is still appealing for all the reasons you mentioned. I noticed the same subjective qualities in the Leica's rendering: greater detail, more subtle gradations in contrast, an overall pleasing image.

I think that with film this kind of A-to-B comparo would be inconsequential, but the digital sensor of the M 240 puts these lenses under exceptionally harsh scrutiny.

 

[uhoh7]

Also, you can pick up a cron asph any day of the week in perfect condition for about 1850. Lots of lenses for Canikony cost as much.

I think it's well established the asph is not perfect. But it's fantastic in reportage wide open. I went with the ZM35/2 because I do alot of landscapes, and I don't think anything really beats the full biogon in that regard.

But the C-Biogon is extremely popular not for nothing. Fantastic lens.

 

[FrozenInTime]

Good test thanks.
I found similar shortcomings with the 35mm Summilux ASPH (pre-FLE in my case).
I added the 35mm C-Biogon to my lenses and use it where the summilux flares badly; where I want maximum full frame sharpness and where the compact size is more important than speed.

 

[bobby_novatron]

The C-Biogon is an amazing lens for the price, new or used. Its optical formula is superb.

Yes, I knew the used Summicron 35/2 ASPH's can be had used for the $1700-1800 USD mark. I tend to keep a close watch on lens prices out of bad habit. 🙂 But that's still about 3x what the Zeiss costs, if you can snag a used C-Biogon.

Like everything in life, there are compromises. The C-Biogon excels at many things -- but for speed and bokeh, you are limited to F2.8, and the Summicron's extra stop could come in handy.

I also find the C-Biogon's trademark 'Zeiss contrast' to be a little heavy at times, to the point where it seems to be obscuring subtle details.

Unfortunately, I did not have access to the new Zeiss Distagon ZM 35/1.4 to add to the mix. FWIW, I will be borrowing one in a couple weeks and I might do another comparison, just for fun.

 

[rscheffler]

It will also be interesting to see how the new Voigtlander 35/1.7 fares in comparison. The fast Voigtlander lenses I have experience with all tend to purple fringe and have some degree of CA, along with more moderate contrast compared to Zeiss.

 

[f16sunshine]

It will also be interesting to see how the new Voigtlander 35/1.7 fares in comparison. The fast Voigtlander lenses I have experience with all tend to purple fringe and have some degree of CA, along with more moderate contrast compared to Zeiss.

They do fringe on digital medium. all those lenses until now were designed for film.
If what peopleare presuming is true,... this new CV f1.7/35mm is designed for digital use.
Let's hope that's true 🙂
It could be a real value lens compared to the Summicron/Summilux duo.
It costs more than the Zeiss lens new (Biogon). It must be special.

 

[anerjee]

Looking at the c-biogon image after the leica image, it almost seems like a layer of haze has been lifted, making the c-biogon image visibly more crisp and pleasant.

I suspect the lighting condition changed subtly between the two shots -- else the difference is not minor.

 

[hellomikmik]

I think you should make a slight shutter speed adjustment (or to bracket) - Leica image looks more exposed, maybe Zeiss lets less light in at f5,6?

Just an observation from my side, I think both of those lenses are toooo good for me.

 

[froyd]

Looking at the c-biogon image after the leica image, it almost seems like a layer of haze has been lifted, making the c-biogon image visibly more crisp and pleasant.

I suspect the lighting condition changed subtly between the two shots -- else the difference is not minor.

Potentially there was as change in lighting,as you suggest, but I would guess the higher contrast and cooler rendering of the Zeiss is a look that appeals more to you, and makes you feel a "haze has been lifted".

 

[bobby_novatron]

I think you should make a slight shutter speed adjustment (or to bracket) - Leica image looks more exposed, maybe Zeiss lets less light in at f5,6?

Just an observation from my side, I think both of those lenses are toooo good for me.

Strangely, I noticed that occasionally the C-Biogon created a different AUTO shutter setting in the M 240, about 1/2 a stop faster. It was as if the Zeiss was capturing a bit more light, but I'm not sure. Unfortunately it wasn't a consistent phenomenon.

I forgot to mention that the metering for these images was used with the M 240's complex multi-field setting under Live View.

FWIW I tried bracketing, and the photos in this thread are the result of that effort: both images are at the same ISO, same shutter speed, same F-stop.

It is possible that the light changed a bit during my shoot. The sky was mostly overcast but perhaps the clouds shifted.

To minimize differences, I deliberately had my camera on a tripod and both lenses nearby for the big switch. There was only about 20-30 seconds delay between images. I wanted to make sure the scenery was as consistent as possible.

I was actually in such a rush that I almost dropped the C-Biogon. That would have been an expensive lesson!

 

[Ronald M]

Photoshop fixes CA.

My ASPH do not have the flat desaturated image shown . Am I looking at a camera JPEG?

My ASPH render nice clean contrasty images like all my other Leica lenses. It does show its age a little, but bit like your example.

 

[bobby_novatron]

Photoshop fixes CA.

My ASPH do not have the flat desaturated image shown . Am I looking at a camera JPEG?

My ASPH render nice clean contrasty images like all my other Leica lenses. It does show its age a little, but bit like your example.

Yes, another thing I forgot to mention: in-camera JPEG.

I wanted to keep processing to a minimum.

 

[LCT]

Well i have both lenses and like them much but (with respect) the f/5.6 images have not the same aperture actually so there are more highlights in one of them hence more purple fringing. I would redo the test at f/6.3 with the brighter lens and i bet the results will be much closer. That said the ZM 35/2.8 is my favorite "slow" 35 ever.

 

[bobby_novatron]

Well i have both lenses and like them much but (with respect) the f/5.6 images have not the same aperture actually so there are more highlights in one of them hence more purple fringing. I would redo the test at f/6.3 with the brighter lens and i bet the results will be much closer. That said the ZM 35/2.8 is my favorite "slow" 35 ever.

Yes I agree, a re-test would be in order. Unfortunately the weather has not been cooperating where I live. The mix of sun + clouds makes consistency a problem.