SL2+Zeiss Biogon 21/2.8 ZM via adapter

[Genoweffa]

Advertisement (gone after registration)

Hi...anyone on the forum that used/using the above combo?

Thanks

[Stuart Richardson]

I have not used specifically the 21mm, but I have used the 25mm, which is a very similar design. Both are symmetrical biogon wide angle designs that were made for film. They do not do well on the SL2. The angle of light coming out of the lens is quite acute, and so it has to pass through a larger thickness of coverglass on the sensor which blurs the results. I found that on the SL2, the 25mm was usable at f8-16 or so, but not particularly good. At any wider aperture it was quite soft and muddy in the edges, getting worse as the lens was opened. It was still very sharp on center, but overall quite soft. Of course, it depends on how close you look, and I did use the lens once or twice for architecture work that did not need to be displayed big, but that is before I got a native wide angle. The 500 dollar Sigma 24mm 3.5 is small and light as well, and much much better on the SL2. It is sharper across the frame wide open than the 25mm Biogon is at f11. They make 21mm lenses as well that I am sure will also be better. Even though they may not carry the Zeiss mystique, the fact that they were designed for the system makes all the difference (also being 20 years newer and designed for digital). If you want a 21mm Biogon to use on the SL2, the SLR versions should do a lot better. Still, I would recommend one of the Sigmas as they are generally excellent, inexpensive, well-built and very sharp...auto focus and auto aperture are an added bonus.

 

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[Genoweffa]

1 hour ago, Stuart Richardson said:

I have not used specifically the 21mm, but I have used the 25mm, which is a very similar design. Both are symmetrical biogon wide angle designs that were made for film. They do not do well on the SL2. The angle of light coming out of the lens is quite acute, and so it has to pass through a larger thickness of coverglass on the sensor which blurs the results. I found that on the SL2, the 25mm was usable at f8-16 or so, but not particularly good. At any wider aperture it was quite soft and muddy in the edges, getting worse as the lens was opened. It was still very sharp on center, but overall quite soft. Of course, it depends on how close you look, and I did use the lens once or twice for architecture work that did not need to be displayed big, but that is before I got a native wide angle. The 500 dollar Sigma 24mm 3.5 is small and light as well, and much much better on the SL2. It is sharper across the frame wide open than the 25mm Biogon is at f11. They make 21mm lenses as well that I am sure will also be better. Even though they may not carry the Zeiss mystique, the fact that they were designed for the system makes all the difference (also being 20 years newer and designed for digital). If you want a 21mm Biogon to use on the SL2, the SLR versions should do a lot better. Still, I would recommend one of the Sigmas as they are generally excellent, inexpensive, well-built and very sharp...auto focus and auto aperture are an added bonus.

 

Thanks.

I do use zeiss 21 slr...was just curious about Biogon.

[jaimepc]

On 9/7/2023 at 4:19 PM, Genoweffa said:

Hi...anyone on the forum that used/using the above combo?

Thanks

Hi! I've been using it with an SL2-S for some time now and I'm quite happy with it. The only time when I struggle a bit with it is on low light conditions (despite it being reasonably fast). It seems like the sensor gets way less light from it than with Leica lenses, and as such the electronic view finder becomes useless and you have to focus by measuring distance. If you're not planning on taking pictures during dark nights, you should be fine.

[jaapv]

Another thing: these lenses are rather difficult (AKA expensive) to repair, asalllens. elements are centered and shimmed separately. I once dropped a 28 and decentered the front lens, and Will had to take it apart lens by lens and rebuild, center and reshim every single lens.

[JRWhite]

On 9/7/2023 at 9:37 AM, Stuart Richardson said:

I have not used specifically the 21mm, but I have used the 25mm, which is a very similar design. Both are symmetrical biogon wide angle designs that were made for film. They do not do well on the SL2. The angle of light coming out of the lens is quite acute, and so it has to pass through a larger thickness of coverglass on the sensor which blurs the results. I found that on the SL2, the 25mm was usable at f8-16 or so, but not particularly good. At any wider aperture it was quite soft and muddy in the edges, getting worse as the lens was opened. It was still very sharp on center, but overall quite soft. Of course, it depends on how close you look, and I did use the lens once or twice for architecture work that did not need to be displayed big, but that is before I got a native wide angle. The 500 dollar Sigma 24mm 3.5 is small and light as well, and much much better on the SL2. It is sharper across the frame wide open than the 25mm Biogon is at f11. They make 21mm lenses as well that I am sure will also be better. Even though they may not carry the Zeiss mystique, the fact that they were designed for the system makes all the difference (also being 20 years newer and designed for digital). If you want a 21mm Biogon to use on the SL2, the SLR versions should do a lot better. Still, I would recommend one of the Sigmas as they are generally excellent, inexpensive, well-built and very sharp...auto focus and auto aperture are an added bonus.

 

Apologies for dreading up an old post.

Stuart - is the “acuteness” of the angle of light a result of being an adapted lens? For instance, would an adapted Elmarit M 24mm f/2.8 show the same issues as the adapted ZM 25mm Biogon? Or are the issues you described due to the lens design characteristics of the ZM? Thanks, Jim

[Stuart Richardson]

Advertisement (gone after registration)

It is really something that is inherent in any given lens design, not a feature of ZM lenses per se. But in the case of the ZM 21 and 25mm lenses, they were designed more for film, and so they did not make an effort to reduce the angle of incidence. I would imagine that the 24mm Elmarit is probably fairly similar, as it was also a film era design, but since I do not have the lens I cannot tell you for sure. What I can say is that lenses made for a given camera tend to be better. If you are interested in a 24mm lens for the L mount bodies, you would be better served by an L mount lens than an M lens. By that I mean that it will be sharper across the frame, you will have accurate exif and aperture information transferred, it will have full autofocus and full weather sealing. If it is a Sigma or Panasonic lens it will also be a lot cheaper as well. It is not that the older M lenses are bad, they are just not designed to work on digital sensors. The wide angles in particular (but also some more standard lenses) featured optical designs which worked extremely well at the time for film, and helped make Leica famous by offering very compact, sharp lenses. But film and digital sensors behave quite differently, and lenses designed for film can sometimes struggle with certain digital sensors. The design of the digital M cameras is specifically tailored to work with film era lenses. The SL cameras can do it, and in a lot of cases can do it very well, but not AS well as the M cameras, whose digital sensors were designed from the ground up for M lenses. Basically an M sensor has millions of tiny lenses covering the sensor, the purpose of which is to take light coming in at a steep angle and bend it back towards straight so that it hits the sensor directly.

This is an old image they circulated, but it should help give you the idea. This kind of fix is not necessary if the lens is designed to be suitable for digital sensors already.

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Edited December 2, 2023 by Stuart Richardson

[JRWhite]

Is this effect less noticeable with longer lenses? Specifically, I will be visiting your neck of the woods in March. Planning to bring along either a CV 90 2.8 APO Skopar or a TE 135mm 4 for use on an M10R and an SL2. Trying to keep the kit tight and was planning only the Sigma 28-70 2.8 as native for the SL2. May rethink that on the wide end and include a Sigma 24 as well (physical size of a 24-70 2.8 seems huge to me after so long with the M system). Am hoping an adapted 90 or 135 will be fine on the SL2. Thoughts?

[BernardC]

39 minutes ago, JRWhite said:

Is this effect less noticeable with longer lenses? Specifically, I will be visiting your neck of the woods in March. Planning to bring along either a CV 90 2.8 APO Skopar or a TE 135mm 4 for use on an M10R and an SL2. Trying to keep the kit tight and was planning only the Sigma 28-70 2.8 as native for the SL2. May rethink that on the wide end and include a Sigma 24 as well (physical size of a 24-70 2.8 seems huge to me after so long with the M system). Am hoping an adapted 90 or 135 will be fine on the SL2. Thoughts?

You won't have a problem with longer lenses. Even the Summicron 50 should be fine, but anything wider than 50 could have an issue, depending on the optical formula.

[Malabito]

if you want a small and relatively cheap 21mm for the sl, look at the Voigtlander 21mm f3.5. Works great on the sl and m systems. It does suffer a bit from some vignetting but nothing that can't be corrected in lightroom. 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!