Flange Focal Distance
Flange Focal Distance is distance from a lens mount flange to focal plane, and this distance is the same, irrespective of the actual focal length as a 10mm lens should focus the rays to the same physical location as does a 600mm lens.
But different cameras have different flange focal distance that makes it impossible to make some adapters. For example, you can't make an adapter between Arri PL and OCT-19 mounts. Or you need to use optical elements like in infinity-allowing M42 to Nikon-F adapter.
I have info on FFD and mount diameter of some movie cameras. Wikipedia has more info.
|
Camera |
FFD, mm |
Mount diameter, mm |
1 |
1KSR-1M (Konvas-1M,-7M,-Automat) |
57±0.01 |
47 |
2 |
1KSR-2M (Konvas-2M,-8M, Kinor-35) |
61±0.01 |
68 |
3 |
US-3H |
61±0.01 |
68 |
4 |
US-2M |
68±0.01 |
68 |
5 |
1-SKL (Temp) |
57±0.01 |
50 |
6 |
Arri-2C |
52±0.01 |
41 |
7 |
Arri-BL2 |
52±0.01 |
41 |
8 |
Arri-BL3 |
52±0.01 |
54 |
9 |
Aaton |
40mm ? |
? |