Hi all,

I am going to be building a large format 4x5 camera and use some paper negatives, I have a few large format lenses already for my speed graphic, however I want to make my own (simple) lens and use waterhouse stops to stop the lens down to make it as simple as possible.

Anyway, I am looking into the lens and am having difficultly working out what I need, I am thinking I would need a lens that has a focal lenth of around 150mm which work be a 'normal' lens on a large format camera. Would any 150mm focal length lens work ok or is there a program I can use to work out what lens I need to get? An example is that I can easily get a 50mm diameter 150mm focal length lens, but how do I know that the image circle will be ok?