Infinity focus not accurate

[Tabosko]

Hello all! I’m puzzled about this situation and hoping to find some insight. I recently purchased a 28mm 5.6 for my Leica m2. In the infinity lock position the focus is off but all other distances are perfect in the rangefinder patch. How is that possible? The lens is able to be adjusted but I fear doing so will cause all other distances to be incorrect.

 

[Sonnar Brian]

Exactly which lens did you buy? I suspect the Summaron-M, but would be good to confirm. This is a newer lens, and would be optimized for digital cameras. It might be slightly off on a film camera. Nothing to worry about.

Does the actual focus agree with the Rangefinder? How far off is the RF coincidence at infinity? Does it focus past infinity?

The DOF of a 28mm F5.6 lens covers a lot of distance. I suspect that actual focus is spot-on.

 

[Tabosko]

Exactly which lens did you buy? I suspect the Summaron-M, but would be good to confirm. This is a newer lens, and would be optimized for digital cameras. It might be slightly off on a film camera. Nothing to worry about.

Does the actual focus agree with the Rangefinder? How far off is the RF coincidence at infinity? Does it focus past infinity?

The DOF of a 28mm F5.6 lens covers a lot of distance. I suspect that actual focus is spot-on.

I got the ttartisan 28mm 5.6 I havent developed any film shot with this lens yet so I'm basing this on what I see in the rangefinder patch. I measured at 2, 3, and 5 meters and they were all spot on far as the patch is concerned with me standing and focusing at this distances. I did suspect that at the focus length that it would be super far out to get to infinity but even when I focus on on clouds far out, the focus at infinity goes past them (meaning there is a point when I lock on, but the focus ring has not reached the lock position and once locked the clouds are back out of focus by a small bit) I suppose at 5.6 its not going to matter.. but this seems odd.

 

[Sonnar Brian]

@Tabosko
The TTArtisans lenses have a user adjustable Cam, and can focus slightly past infinity while working properly on different cameras. They need some margin for adjustment.
SO- this is "A feature, not a flaw"...

 

[Tabosko]

@Tabosko
The TTArtisans lenses have a user adjustable Cam, and can focus slightly past infinity while working properly on different cameras. They need some margin for adjustment.
SO- this is "A feature, not a flaw"...

Yes I’m aware that it can be adjusted. Just didn’t want to so at the cost of creating a problem that as you pointed out isn’t truly a problem. Thanks for the help!