How to calculate subject distance to fill image?

[Ian Grant]

Why not just look at the ground glass?

The OP says that's not an option. However it might be an idea to do the testing on a camera where you can.

Ian

 

[wiltw]

Why not just look at the ground glass?

OP had said, " Due to the peculiar camera set up I am using I can't actually focus through the ground glass"

The OP says that's not an option. However it might be an idea to do the testing on a camera where you can.

Ian

OP said, "Due to the peculiar camera set up I am using I can't actually focus through the ground glass ... and then final focus using the Betterlight scanning back that I have.

 

[gert]

Hi all.

After some searching I am still confused as to how to calculate lens plane to subject if I want to fill a 5 inch wide (4x5 Sinar) image with a flat subject whose maximum width is 48 inches. I am using a 150mm Symmar lens. Due to the peculiar camera set up I am using I can't actually focus through the ground glass so I am trying to put the system into the ball park orientation (lens to subject, lens to film plane) and then final focus using the Betterlight scanning back that I have. If someone can point me toward the correct set of formulae with a working example I would appreciate it greatly.

Thank you

I recently got an older scanback Dicomed but have difficulty getting it started. do you have any insights on this? I got it with a powerbook with PS8