Spiderless Reflector

I have an old Celestron 10" f1.5 Camera that has no primary but it does have the front 10" round (optical flat?) glass window. Is that glass considered to be flat enough so I can glue a seconday in the middle and add a good 10" f/4 mirror and a focuser and have a reflector with no spider of a good quality? I know those cameras were made for low power imaging, so will it take high power ok with that glass in the way?

Thanks, oren.

[COLOR="Purple"]That front piece of glass is indeed an aspherical corrector (usually made by deforming the glass plate with a vacuum while polishing, IIRC). Using a parabolic primary with it would probably not work too well.
Bill[/COLOR]

Oren Soffer said:


I have an old Celestron 10" f1.5 Camera that has no primary but it does have the front 10" round (optical flat?) glass window. Is that glass considered to be flat enough so I can glue a seconday in the middle and add a good 10" f/4 mirror and a focuser and have a reflector with no spider of a good quality? I know those cameras were made for low power imaging, so will it take high power ok with that glass in the way?

Thanks, oren.

What the--?!

What you have is a Schmidt Camera. That's not a flat piece of glass, that's a lens.

What you most likely have is the Schmidt camera "nose" of the convertible version of the Celestron 10 from mid 1960s. The SCT front end inclusing its corrector and secondary came off, and this piece mounted instead. The glass at the front is a Schmidt corrector and not flat, altough deviations are too small for the eye to readily see. Design was for F2 primary (spherical) with image plane halfway between primary and corrector (internal to the tube).

Dave

Oren Soffer said:


I have an old Celestron 10" f1.5 Camera that has no primary but it does have the front 10" round (optical flat?) glass window. Is that glass considered to be flat enough so I can glue a seconday in the middle and add a good 10" f/4 mirror and a focuser and have a reflector with no spider of a good quality? I know those cameras were made for low power imaging, so will it take high power ok with that glass in the way?

Thanks, oren.