Filter adjustment on Rolleiflex F cameras

[JG Motamedi]

I don't understand the filter exposure adjustment on the side of the Rolleiflex F cameras. Is it filter factor or stops?

My understanding from the manual is that the filter exposure adjustment wheel on the ASA/DIN adjustment knob is marked in filter factors. So, turning it to 1.5 for a medium yellow filter would increase the exposure by 2/3 of stop. However, on my camera (3.5F version 3) it seems to adjust in stops, not filter factors. Turning it to 1.5 means that I am exposing 100 ISO film at about 38 ISO, not 64. Can anyone confirm?

Thank you.

jason

 

[piu58]

This are stops.

 

[JG Motamedi]

Thank you. The manuals were unclear about this. It does seem odd, as Rollei filters are marked by filter adjustments, while they mark it on the camera by stops.