I acquired a aerial camera lens with the following data Maker: Pacific Optical 12 in f3.8, EFL of 303mm,and a FD of 10.328 in
It has two elements which are separated by the original mounting distance-- 112mm.
Now my question is what would happen to these parameters if I increased or decreased the spacing between the two sets of elements.
They are very heavy and naturally I didn't think of changing anything until they were mounted. I checked around the internet but nothing came out.
I would like to use it as a camera lens ,but a telescope objective would be a good second choice

Thanks
rob