Kiev 60 and similar P6-Groundglass-focussing
I am about to check out which groundglass without fresnel is needed on filmlevel to check focus on kiev 60. I have results already. used laser-distancemeter at 3m, also 1m checked. Volna 80mm.
have original Screen inside. Araxfoto telling its 1.7mm thick. didnt remove yet but should be the same. have got both brightscreens of richard oleson -one has split. since they are tiny they do not fit inside back well. they cannot be trusted. they are for viewfinder.
So i tested Groundglasses of different thicknesses. also old one from HB-V, the coarse one without fresnel.
Background of this test was the idea of using ONE universal Groundglass for all my cams. Kiev 60, Bessa I(6x9), Mamiya Universal Press, RB-backs.
I have my doubts that i can use the same matching Kiev60-groundglass also on e.g.Bessa I.
Groundglass-thickness/Lens-scale at 3m
1.3mm/3.2m approx. since no 3.2mm-setting GG from Toyo Quick Roll back G.
so Groundglass must be 1.7mm to show 3m if sharp. and thats the very same dimension like Screen has.
On Bessa I with other lens-construction/bellows, which thickness of Groundglass is needed? can only test with film. i "calibrated" lens, also rangefinder but maybe wrong Groundglass used.
Have interesting report by Ron Wiesner about Groundglasses and fresnel(from archive.org) but has nothing to do with this problem here.
Other cam is nettar 6x6. and various RB- or G-backs. Graflok 23.