I'm making initial plans for a 14x17 ULF camera. I foresee one day having a 30-inch (760mm) as my longest focal length. I'm also thinking that I'll make bellows about 40 inches long, though that is obviously a flexible factor. I'm wondering if there is a formula, or even a calculator, to determine how close I'd be able to focus a given focal length lens with a given bellows draw. I know I'd need 60 inches to focus 1:1, but what about intermediate distances? I'm not a math guy, so haven't been able to figure it out myself.

I've found some info online, but not just what I'm looking for. Figuring out what search terms to use is probably my problem.

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