Image circle on process lenses

[Herb Cunningham]

I have several process lenses, but i am getting overloaded on 240-300mm lenses, and want to thin out the herd.

I have a Nikkor Apo 240mm f 10 process lens that a web site I looked at said has a 720mm image circle, which I would think would be at 1:1.

Anybody know for sure the max format for this lens? It is in a copal 1 shutter, mounted by Grimes.

[Bob Salomon]

Just point it out the window with a sheet of white paper behind it. Move the paper in and out till you see a sharp image circle. That is the coverage at the distance the obeject the lens is pointed at is.