My very limited knowledge of Maksutov lenses was that they had a
pronounced spherical curvature to the corrector lens. Is the focal
length/aperture of common camera lenses such that these can be nearly
flat? IRRC the Maksutov was used for slower lenses, the Schmidt
Cassegrain(sp?) for faster?
I believe most of the Celestron lenses are Schmidt Cassegrain.
IRRC the Questar is a Maksutov and has a great reputation.
-jeff
----- Original Message -----
From: "Chuck Norcutt" <chucknorcutt@xxxxxxxxxxx>
>
> The photographic lenses also tend to be Maksutov designs probably
> because the secondary can be designed such that it's nothing but an
> aluminzed spot on the back of the Maksutov corrector lens. No
> additional mechanical support or adjustments required. However, I
think
> the Maksutov corrector lens is thick enough that chromatic abberation
> could be a design concern. Also, over about 90-100mm diameter the
> Maksutov lens begins to get very expensive to manufacture. The
Schmidt
> corrector plate is so thin and so nearly plano-parallel that chromatic
> abberation is not a worry and (for the last 30 years or so) is
> relatively inexpensive to build in large diameters.
>
> Having said all this I just decided to check the optical layout of the
> Oly 500mm reflex and see that it is not a Maksutov design. I was
> surprised at the number of refractive elements.
>
> Chuck Norcutt
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