Azzure_7 wrote in post #13355484
Well, how do they measure camera to subject distance?
The lens tip of the 85L is sure longer than the 1.8.
So the 1.2 will be nearer to the subject.
Camera/subject distance is exactly that: from sensor to subject.
If the FL of the 85L is a little less than 85 mm, it may well show more in the frame (or vice versa).
FLs generally are nominal values only, unless specifically indicated, like Leica did on some on their lenses (individually, up to 0.1 mm accuracy), and Pentax did with their special edition lenses (still nominal though, although more restricted, see below). It is considered acceptable to round the FL within 5%, up or down. IOW, 85 mm may be anything between approximately 80.5 and 89.5 mm, which is more than 10 % of a difference, potentially, between two lenses which are nominally 85 mm.
BTW, not even two lenses from the same production line, same model, have exactly the same FL - even those may vary within a few mm (as those individually marked Leica lenses did show, f.e.).
HTH, kind regards, Wim