M to L adapter effect on result?

[HeavyEd]

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In regards to an M to L adapter, I wonder how the added offset/extension from the lens to the sensor effects the outcome of the photo. 

Minimal maybe, but does anyone have a better understanding of what the actual results are? I feel as though it throws the manual focus off quite a bit. And with that, a slight degradation 

in the image output. I may be wrong, but I am interested in hearing others opinions on this.

Thanks in advance.

 

[jaapv]

None -the only thing an adapter does is to correct the flange distance to the actual register distance of the lens (i.e. put the lens at the same distance from the sensor as the native camera to enable the lens to focus correctly. It does not "throw the focus off" (???) if it is properly made. Just the opposite.

[Photoworks]

your marking to infinity may not be correct on the lens, by design, the lens focusing goes past infinity. this is to compensate the material expansion with changes of temperatures.

If you are using adapters from China, they can be correct or sometimes they need calibration, but you will notice it in the camera when focusing.

[HeavyEd]

32 minutes ago, jaapv said:

None -the only thing an adapter does is to correct the flange distance to the actual register distance of the lens (i.e. put the lens at the same distance from the sensor as the native camera to enable the lens to focus correctly. It does not "throw the focus off" (???) if it is properly made. Just the opposite.

None????? Interesting. Thanks.

[HeavyEd]

20 minutes ago, Photoworks said:

your marking to infinity may not be correct on the lens, by design, the lens focusing goes past infinity. this is to compensate the material expansion with changes of temperatures.

If you are using adapters from China, they can be correct or sometimes they need calibration, but you will notice it in the camera when focusing.

Thanks.

[GFW2-SCUSA]

I use the Leica M to L adaptor often and find that is has no effect on the image quality. It allows us to use M lenses which are wonderful on SL and CL cameras. 

[jaapv]

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10 minutes ago, HeavyEd said:

None????? Interesting. Thanks.

As far as the lens is concerned it is mounted on its native camera mount. Apart from (sometimes) transferring electronic data the adapter is passive. 

[LD_50]

1 hour ago, HeavyEd said:

In regards to an M to L adapter, I wonder how the added offset/extension from the lens to the sensor effects the outcome of the photo. 

Minimal maybe, but does anyone have a better understanding of what the actual results are? I feel as though it throws the manual focus off quite a bit. And with that, a slight degradation 

in the image output. I may be wrong, but I am interested in hearing others opinions on this.

Thanks in advance.

 

As mentioned the adapter puts the lens the correct distance from the sensor. Unless the mount or adapter is out of tolerance, there should be no impact on manual focus results. You may see lower IQ than an M with some lenses, but that’s the sensor design, not related to the adapter. 

[Stuart Richardson]

You may see a difference in performance, but that would be because of the difference in bodies, not the adapter. As the others say, if the adapter is made properly, it will have no effect at all on the focus or optics. But if you are seeing slightly worse results, it might be because the stronger microlenses or thinner cover glass in M cameras. Many M lenses, especially older wide angle lenses, are a little bit better in the corners on M bodies than SL bodies. You are unlikely to see a difference in normal lenses or telephotos.

[HeavyEd]

50 minutes ago, Stuart Richardson said:

You may see a difference in performance, but that would be because of the difference in bodies, not the adapter. As the others say, if the adapter is made properly, it will have no effect at all on the focus or optics. But if you are seeing slightly worse results, it might be because the stronger microlenses or thinner cover glass in M cameras. Many M lenses, especially older wide angle lenses, are a little bit better in the corners on M bodies than SL bodies. You are unlikely to see a difference in normal lenses or telephotos.

Makes sense.......

Thank You Stuart

[Mak67]

Well, all this is true execpt for FLE lenses, due to the fact that they are a bit shorter than they should to ensure infinity focus with material dilatation ... Then, relation between lens focus, fle and real point focus is a bit off, at medium or closed distance.

I've tried 3 différents Leica M/L adapter and they all were quite variable regarding distance ajustement.

[jaapv]

3 hours ago, Mak67 said:

Well, all this is true execpt for FLE lenses, due to the fact that they are a bit shorter than they should to ensure infinity focus with material dilatation ... Then, relation between lens focus, fle and real point focus is a bit off, at medium or closed distance.

I've tried 3 différents Leica M/L adapter and they all were quite variable regarding distance ajustement.

Only if the adapter is so much out of tolerance that the difference is significant. A minor focus past infinity is neither here nor there. When you get the system so hot or cold that the expansion or shrinkage gets to be a factor the same would be happening to a native body-or a lens barrel.

[HeavyEd]

5 hours ago, Mak67 said:

Well, all this is true execpt for FLE lenses, due to the fact that they are a bit shorter than they should to ensure infinity focus with material dilatation ... Then, relation between lens focus, fle and real point focus is a bit off, at medium or closed distance.

I've tried 3 différents Leica M/L adapter and they all were quite variable regarding distance ajustement.

Thanks Mak......

The closed distance seemed to be off to me......thats what got this ball rolling......being new to the M system and all. I hate blaming gear when it could easily be, in my case,  operator failure.......lol.

Thanks for your insite.

[jaapv]

If you focus on an EVF camera the image cannot be unsharp unless you get it wrong in the viewfinder. You see what the sensor records...  Disregard the distance scale. It is only approximate at any time. 

[UliWer]

vor 15 Stunden schrieb Mak67:

Well, all this is true execpt for FLE lenses, due to the fact that they are a bit shorter than they should to ensure infinity focus with material dilatation ... Then, relation between lens focus, fle and real point focus is a bit off, at medium or closed distance.

Sorry, but I do not understand what ou are talking about.

The focussing system of any M-lens - whether it has floating elements or not - is totally independent from the adapter. It has to be so, otherwise it wouldn‘t work without adapter on an M-body. If a FLE-lens was really shorter than it should be, it would not work properly on the M. 

So either the adapter is right when it exactly substitutes the missing distance between flange and sensor, or it is wrong. If it is too long, you won‘t be able to focus sharp on infinity, even if the lens is set on the infinity mark. If it is too short, you perhaps will get a sharp image in a small range, but neither on minimum focussing distance nor at infinity. 

 

[jaapv]

Yes you are absolutely right. However, if the adapter is far too short you need to extend the lens  by the focus ring to compensate. On an FLE lens that will impact the correction by the floating element as the nominal focus setting of the lens does not match the actual focus. 
At least, I think that is what he means; I have no idea whether this theory makes any sense at all-in fact I don’t think that it makes  sense as the only thing that an adapter does is to position the plane of focus. 
one thing a really badlv made adapter can do is skew the optical axis 

[Genoweffa]

On 3/2/2025 at 8:12 PM, Photoworks said:

your marking to infinity may not be correct on the lens, by design, the lens focusing goes past infinity. this is to compensate the material expansion with changes of temperatures.

If you are using adapters from China, they can be correct or sometimes they need calibration, but you will notice it in the camera when focusing.

My both adapters to L (for M and ZE) work fine....but @ infinity I have to come back a tiny bit for the spot on focus...is this because of what you mentioned above? 

Edited March 7 by Genoweffa

[jaapv]

1 hour ago, Genoweffa said:

My both adapters to L (for M and ZE) work fine....but @ infinity I have to come back a tiny bit for the spot on focus...is this because of what you mentioned above? 

Correct. 

[UliWer]

Hmmm, there are some long telephoto lenses for the R-system which for the reasons explained above can be focussed further than the index for infinity. Though I don‘t know any lens for the M-system which has this feature. Even with the long focal lengthes to be used with the Visoflex (Telyt 200, 280 or 400mm) the focussing stops right at the index for infinity.

So either there really is some issue with the adapter or the object you tried wasn‘t at infinity but a little bit closer.

Edited March 8 by UliWer

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[Stuart Richardson]

I think adapter makers usually slightly cheat towards focusing past infinity for the reason that Jaap explained...if you go slightly past infinity, the lens can still be focused spot on at infinity, whereas if the adapter is slightly too thick, then you will never be able to achieve infinity focus. Getting it exactly right is very tricky, especially with 60mp and 100% detail on long lenses wide open. This was not such an issue when the lens with the shallowest depth of field was a 90mm f2 that focused to 1m and on film. But with the APO lenses and high speed/high sharpness lenses we have now on extremely high resolutions, getting infinity focus perfect is extremely demanding on tolerances. It cannot be so tight as to be difficult to mount and unmount the lens, so I think that making it nanometer perfect is too tall a task for an adapter, where you are adding two more mating surfaces. Tolerances multiply, so instead of just having the machining and spacing tolerance of the lens mount and the lens rear mount, you have both of those as well as the precision of the machining of the adapter rear mount, the width of the adapter overall, and the machining and tolerance of the front mount. All have to be tight enough to place the lens exactly, while still being loose enough to smoothly mount and dismount both the adapter and lens. Doing it is not that hard, but doing it perfectly is very hard.