Originally Posted by Valkir1987
Option 1 can only be done with option 2 number two.
Check the flange to film distance and infinity focus first. If these parameters are correct and the focus at 1m is off it comes to shimming the optical part.
I always forget wether the actual dept of field is larger in the front or the back of the focus. But it its something which comes into consideration when de lens is set to infinity.
Don't forget to check the accuracy of your rangefinder first. If your rangefinder is off, you are messing up your lens. This is not very likely in the case of the gear you have, but better start from there.
Thank you for sharing your thoughts. The ZI is properly adjusted, as all my ZM lenses (35/2, 50/2, 50/1.5) focus accurately (the only one that misbehaves is the Sonnar, due to its inherent focus shift).
Since my first post, I actually put in practice option no. 2 and it works fine. I still have to run a few tests, but, at least at minimum distance (90cm), the focus is now spot on (or perhaps 5 mm backwards). Regarding your question about the dof, the ratio between front and back varies according to distance. At very close distance, it's usually 49/51. At a distance of several meters, it is roughly 33/67.