Questions tagged [cassegrain-telescope]

Questions about reflecting telescopes that use a concave primary mirror and a convex secondary mirror, such that the focal point is behind the primary mirror.

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What Crayford focuser to buy for a B&L Criterion 8000?

I'd like to get a dual-speed Crayford focuser for my newly acquired a B&L criterion 8000 (8") as the mirror shift is pretty bad. I'm really not sure which one to buy because I'm quite ...
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2answers
125 views

Why are Cassegrain telescopes shorter than Newtonian reflecting telescopes?

Many websites say this is because the effective focal length of the objective is increased by making the secondary mirror convex. This allows a Cassegrain telescope to be shorter than a similarly ...
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Second Telescope: Maksutov Cassegrain vs Refractor

I bought my first telescope, a 3-inch refractor a few weeks ago. It has been a wonderful experience seeing the Moon, Jupiter, Saturn magnified and Andromeda, M33, M81 and much more for the first time. ...
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Under what situations can an aperture mask improve the resolution of a small/medium amateur telescope? Is this demonstrable mathematically?

@antlersoft's answer describes some of the challenges to seeing any details in the small disk of Mars in small amateur telescopes. In the case of reflecting telescopes, it mentions the use of either ...