Originally Posted by peewee
I recieved a used 28mm Biogon yesterday. I like the lens a lot.
However at closest focus distance @ 2.8 the subject is a total blurr and does not sharpen up completely until either the distance is 1m or set to f8.
Is this usual?
Thanks in advance
Hi -- The Biogon's closest focus distance is 0.5m, whereas the M9's RF can track focus down to about 0.7m. So there's a small range from 0.5m to 0.7m where the camera's RF patch doesn't move at all.
So, this close focus can be handy with the lens adapted to something like a micro-4/3 camera, but on an M type RF camera you have to be watchful for the de-coupling point. Any focusing closer than ~0.7m should be judged carefully by eye or tape-measure.
And, yep, this is normal for several wide Zeiss ZM lenses.