>>3206927> m39/ltm has a shorter flange distance than m42Yep!
> m42 can be adapted to Canon EFWith you so far!
>Logical consequence: As m42 has a longer flange distance than m39/ltm, but can be adapted to EF, m39/ltm can also be adapted.Annnnd you’ve gone off the rails. That’s like saying “this couch fits in my friend’s pickup truck. My geo metro is smaller than a pickup truck. Logical consequence: this couch will fit in my geo metro”.
To focus correctly, a lens has to be at its proper distance from the focusing plane. If the flange focal distance expected by lens A is significantly LONGER than the flange focal distance provided by Camera X, that’s not usually a problem. You just build an adapter that rests the adapter mount far enough forward that the lens is where it wants to be.
If the flange focal distance is SHORTER, though, you have a problem. There’s stuff in the way of where you want the lens to be, like a reflex mirror. That’s why you never see rangefinder lenses adapted onto SLRs. The only way to adapt it is to make an adapter with corrective optics in the middle that adjust the plane to which the lens focuses. This will also change your focal length, effective aperture, and if it’s a cheap adapter, probably fuck op your image quality because it’s adding shitty cheap glass into your optical system.
