B4 mount, flange focal distance measurement.

[Gregg MacPherson]

In case this question got lost or wasn't well identified in my other post, I thought I'd try with a better title.

If I have a B4 mount lense but no camera mount or adaptor, where on the lense flange do I measure the flange focal distance from?

Cheers

Gregg.

[Dom Jaeger]

The flange focal depth or distance is measured from the camera mount/rear of the lens mount flange to the film plane.

[Gregg MacPherson]

Thanks Dom,

Just to be really clear. The flange on the lense has three wings or tangs that stick out, then it's steped down to a smaller diameter behind this. I thought that flange focal distance would probably be measured from the rear of the flange with wings on it, but wanted to make sure that it wasn't from the rear of the steped down flange.

 

Like I said in my other post, I was curious to clamp this lense (Canon J15x9.5B ) on a bench in front of my Eclair ACL. I don't know if it will properly cover the frame and I don't know how sharp it can be.

 

Cheers

Gregg

Edited September 22, 2010 by Gregg MacPherson