Schmidt-Newtonian --> Schmidt camera?

Hello:
Here's an idea I've been kicking around a little while, and I'm wondering if anyone has thought of, or actually, made something similar. It seems like a Schmidt camera is the way to go for fast, wide field imaging. Making and using one is a bear. A Schmidt-Newtonian has the advantage that the focal plane is not in the telescope, which makes focusing and alignment easier, and allows the use of larger camera bodies and CCDs. It occurred to me that the Meade Schmidt-Netwonians are almost what you need. In theory, all you'd have to do is put the corrector plate at the radius of curvature of the mirror (from what I've read, the correction for spherical aberration does not depend on the separation between the primary and corrector plate, although the coma does), and make a field flattener. If the primary mirror is the same size as the corrector, then it'd probably be best to stop down the aperture at the corrector so the pupil is at the corrector plate. Naturally, all of this is easier said than done, but I suspect it's within the realm of possibility for many. This is all the more attractive since 8" and 10" Schmidt-Newtonian OTAs are available on Astromart fairly cheap. Is there anything fundamentally flawed about this scheme? Has anyone tried this out?

Cheers
Mike Connelley

Hello:
I should have mentioned that, as I envision it, the Newtonian secondary mirror would be kept to place the focus outside the tube where it can be accessible, and so that a conventional focuser can be used. This would require adding a spider since the corrector plate can no longer support the secondary. Field curvature is the main hurdle to making this idea practical. Since the field curvature depends only on the focal length of the primary mirror, one could reduce the field curvature by using a longer focus mirror. Unfortunately, this leads to a rather long focus system. For example, an 8" schmidt camera could go without a field flattener (or bending the film) if the focal length is more than 2.5m. In such a case, the curvature of the field would increase the size of a star 1" fron the center of the field by 10 microns. Thus, the tube would be 5m long and the camera would have a f/12.5 speed. At this point, the advantages of a schmidt system are lost.

Cheers
Mike Connelley