Discussion:
Rollei 35 mm SLR Flange focal distance...Prochnow's Rollei Technical Report data
CarlosMFreaza
2014-09-09 19:27:06 UTC
Permalink
I forgot Prochnow's Rollei Technical Report book yesterday, I found
this info for the Rolleiflex SL35 (page 3-225):

" 4. Adjust and check infinity- setting and optical axis (with gaugue
and on collimator).
Plane measurement and optical axis measured with gaugue L-8613: 44,67
+ 0,02mm . Note: Measured from lens contact surface of bayonet ring to
the pressure plate-plane"

"Focusing screen Plane measured with collimator
44,50 +/- 00,3mm = 0 +/- 3 graduations (75/80 scale)"

I add that the figures from "0" are for the Rollei collimator

And then both figures 44,67mm and 44,50mm are used for the Rolleiflex
SL35 cameras optical adjustment, the first one for the lens register
and the second one for the focusing screeen plane.

I think 44,67mm is the figure to keep in mind for a QBM lens adapter
to a non QBM camera.

Carlos
Perhaps it would be necessary to clarify if Dirk needs the back focal
distance, 44,50mm to assure a right focus for the QBM lenses with the
adapter for Canon, or if the mechanical distance 44,67mm is enough to
assure it or if both distances are the same for practical purposes.
yesterday and they give the back lens distance to film in their
technical info, f.e. according the Planar 1.4/50 Contax /Yashica
technical sheet the lens back distance "to film" is 45,50mm (there are
no technical sheets on line for QBM lenses).
Carlos
This is the Contax/Yashica mount Planar 1.4/50 lens technical sheet,
it could give an idea baout the way Carl Zeiss measures the 44.50mm
http://www.zeiss.com/content/dam/Photography/new/pdf/en/downloadcenter/contax_yashica/planar1-4_50mm_yashica_e.pdf
Carlos
Loading...