[Leica] Accuracy of x.72 range finder

[Peter Niessen <niessen@ifh.de>]

Dear all,

in his famous article ,,J'accuse Leica'' Mr. Ross proposes the
following experiment:

Place a Leica M 2m apart from an object, focus, move 6mm away and
check if you can see a difference. He states that the depth of field
for the 75mm Summilux is 6mm at 2m distance. Is that really true and
not a typi? Common Literature tells that d.o.f. is 6cm.

However, I wonder about two things:
1. Can you see a difference with an SLR there?
2. Are there other errors on the range finder? Is there a formula
which tells you delta_d = delta_d (distance, aperture, rf_base, ...)?

Cheers, Peter.

Peter Nießen
e-mail niessen@ifh.de