> I have started a 8 inch lenseless schmidtt camera based on an article by
> Peter Ramberg in S & T a couple of years ago. Its a 8 inch f3 spherical
> mirror with a baffle at the radius of curvature to reduce the f ratio to
> f4.5 to 5 to control spherical aberration and still be fast enough to take
> photos with relatively short exposures. Apparently this is the optimum trade
> off between speed, spherical abberation and curved focal plane.
>
> I've got the mirror ready to figure and would welcome any comments from
> anyone that has any experience with the set up or general comments on the
> concept before I get too far.
I did some calculations on the resolution of these lensless Schmidt designs and found that the spherical abberation at f/4 to f/5 is still about 0.03mm. While this is fine for grainy high-speed films, emulsions like tp2415 will require a better resolution (about 0.01mm) to achieve a true Schmidt feeling.
So consider to make a Schmidt corrector plate and a faster system.
Hartwig