Saturn

[SteveDallas]

Originally posted by Elspode
What is the focal length of the ETX 90? I'd really like to move up to one of these little (are they Schmidt Cassegrains?) scopes from my DS 114 (114 mm fl 5") reflector someday soon.

It's 1250mm, for a focal ratio of f/13.8. And it's a Maksutov-Cassegrain. I believe the difference is the corrector plate is curved.

The GOTO setup, though...that is sweeeetttt...don't knock it until you've tried it. The ETX's have the clock drive base already, yes? I thought they were easily adaptable for the Meade handboxes?

Oh, I know, I actually have the goto with my ETX-70. But it is not that fabulous a planetary scope. The goto is great for dim objects with no stars nearby to guide you. But the ETX-90AT (with goto) is running for $600. I decided for a $300 difference, for my purposes, I could do without the goto. This particular ETX, the original, just has an RA motor, no dec, and no way to fit it with the Autostar boxes.

I used a photo package called Picture Window Pro to do the stacking. There is a more specialized astro package called Registax that I couldn't get to behave, that I need to work on more. But I had Picture Window and knew how to use it already.