Leica M to Nikon Z Adapters -- Observations/Questions

[das]

I have been going through a bunch of Leica M and screw mount lenses on a Nikon Z6 on a cheap Fotasy adapter. There are few things that seem consistent across all sorts of lenses. Most lenses when shot at wider apertures appear to focus "just short" of infinity. Somewhere in the mid-range, the lens focuses accurately at infinity in accordance with the lens markings. At the smaller apertures, the lenses focus past infinity -- sometimes rather significantly. Some lenses are worse than others. The Voigtlanders 21/4 and 35/2.5 actually seem to have the least amount of issues. Of course, Live View solves all of this in reality as you can focus in real time.

I understand that many of the cheap adapters are not tall enough -- thus, it can be expected that some lenses may slightly overshoot infinity. However, that does not explain underfocus. I was wondering if there was any way to solve any of this. A taller or shimmed adapter means no more focus overshoot at infinity, but will only worsen the underfocus at wider apertures.

I guess I can only conclude that many Leica mount lenses do backfocus at wider apertures and possibly focus beyond infinity at smaller apertures in real life?

Are you folks seeing the same thing?

 

[Timmyjoe]

Not seeing a problem. I've got a cheap Chinese made adapter, maybe a Fotasy, because when I got my Z6 last year, there were no other Leica M to Nikon Z adapters available. Wanted a Novaflex, but couldn't get one. I've never had any focus issues with the one I got, so when the Novaflex adapters became available, I saved the 200+ dollars.

You do realize that with the EVF, the camera is alway shooting in live view. What you see in the EVF is what you get.

Sorry you're having issues.

Best,
-Tim

 

[das]

Thanks, Tim. Yes, I understand that. What I'm more concerned with is how the lenses operate on non digital platforms. If the adapter is a neutral factor, lenses are still under and overfocusing in different circumstances. So, for instance, on a film camera, shouldd one be focusing at 10m instead of infinity with a certain lens at f/8 when the subject looks to be at infinity? Digital has much to teach about these things, it seems.

 

[oldwino]

I think you’re overthinking it.
With my Kipon adaptor on my Z6, none of the distance scale markings are precise. So if I wanted to zone focus at 10 feet, I’d probably have to set the lens at 6 or 8 feet, for example. I think they build these things to focus “beyond” infinity, to make sure that infinity can be reached.
But with the live view, that’s all really not a problem.
And all of my M lenses on my M hit infinity at the infinity mark, and 10 feet at the 10 foot mark, so it’s not the lenses.

 

[Huss]

Like Oldwino mentioned, they all should focus slightly past infinity as this guarantees that they have a complete focusing range. They cannot be made to focus to infinity as the mfg knows that many different types and brands of lenses will be used with the adapter, all with varying degrees of tolerance and wear.
You could shim it, but I have not bothered with mine, as that would only be good with one specific lens.

 

[Larry Cloetta]

Thanks, Tim. Yes, I understand that. What I'm more concerned with is how the lenses operate on non digital platforms. If the adapter is a neutral factor, lenses are still under and overfocusing in different circumstances. So, for instance, on a film camera, shouldd one be focusing at 10m instead of infinity with a certain lens at f/8 when the subject looks to be at infinity? Digital has much to teach about these things, it seems.

If, I am understanding correctly, the problem you are having is with Leica M lenses which are used with film cameras, not Nikon Z cameras and not M to Nikon Z adapters.?

 

[albertospa]

If I understand the problem correctly, I don't think the adapter is responsible. Many lenses, especially the brightest ones (including the f2) suffer from small shifts in focus with respect to the various apertures and the various distances. If the distance between lens and focal plane is not perfectly respected, the problem is even more evident. But all of this doesn't matter if you control the focus with EVF. I believe that even with a Novoflex adapter it will be difficult for the focus with EVF to match the focus shown on the lens scale.
This happens sometimes even when comparing the focus in a digital Leica with evf (M240, M10) and rangefinder.
With your Voigtlander lenses the problem is less because they are not very bright lenses and maybe even better coincidentally collimate with your adapter.

 

[das]

Thanks, everyone. I usually use digital mirrorless cameras to test how a lens behaves so as to learn better how to shoot them on film for optimal results. With all the talk over the past decades about "focus shift" -- on mirrorless is really becomes apparent where focusing is 100% unforgiving at true pixel depth. What has surprised me is that the cheaper Voigtlander lenses are actually better at controlling the shift than many other older and more expensive rangefinder lenses. Even cheap lenses like the Jupiter 3 is so off that you can't even shoot at infinity at less than f/8.