Zeiss Planar 50mm f2 DOF Anomaly

[Mjd-djm]

For some reason my new (to me) Zeiss Planar lens appears to be front focussing. Whenever I take a picture at distances over 10 or 15 feet at f2 the vast majority of the DOF is in front of the subject I focussed on. The subject usually appears to be just in focus, sometimes out of focus, with the grass or whatever in front of the subject in sharper focus. The lens focuses perfectly to infinity on my Leica M4-P. Anyone have any ideas what is wrong? Is it possible the lens has been shimmed?

 

[Dante_Stella]

Nominally, 1/3 of the DOF is supposed to be in front of the focused subject and 2/3 behind, but in practice, fast lenses usually bias toward front focus (subject and in front) at larger apertures and then toward focusing at and behind the subject at smaller ones.

 

[Rob-F]

So, the take-away here is that the lens appears to be front-focusing (more so than suspecting a DOF anomaly).