Mak-Cass contrast

I used to have an ETX Mak-Cass. My primary memory is that the contrast was far better than my SCTs.

Is this because of the smaller CO? Seems unlikely, as the SCTs I've viewed through were 33% - 38%, and I think the Mak-Cass is 32%.

Is it because of the long focal length? In other words, I'd usually be using more magnification per inch of aperture and so the background looked darker?

Or is the Mak-Cass easier to baffle because of its design?

Or is the design somehow easier to get a higher polish on the glass, and therefore less scatter?

Or something else?

Thanks,
-- Jeff.

I will guess that

(1) The ETX has smaller aperture so everything
(reflections, sky, etc.) looks dimmer for a given power.

(2) The strong curves on the Mak corrector plate tend to
dispell any internal reflections, which is not true of the
SCT. But this will only be a small effect.

In all spherical Mak Cass., even in the cheaper machine made units, you can expect to find smoother optics than the much complex aspheric SCT’s. With smoother optics more of the light comes to focus giving you tighter and cleaner images than the SCT’s, this also translates in better contrast when comparing the two systems with the similar obstructions.

Vahe