15" scope operational again.

[johnridley]

I got the mirror cleaned. Damn, it was filthy. Also I chased a lot of cobwebs out. It still needs some work but it's at least usable and still a damn fine instrument. I should do some work on the elevation bearings, I never got them quite right, just good enough.

I found it interesting that I can see more stuff in the SPOTTING SCOPE of the 15" than I can with the Astroscan, even though the spotting scope is just an 8x50mm, and the Astroscan is a 4.25".

The notes are here.

Comments

Any chance you can snap some photos?

[techgrrl.livejournal.com]

I have a 4.25" but do not use it much, too much light pollution to do much more than view some planets. I'd love to see some snapshots as done from a 15" scope.

Re: Any chance you can snap some photos?

[johnridley.livejournal.com]

I don't have any astrophotography equipment. Besides, it's not really possible to properly convey in a photo what things look like in the eyepiece.

Here's an interesting image, from Obsession Telescopes:

If you take the 8" view and imagine that 1/4 as bright, that's about right for a 4" scope. Then look at the 15" on the right. Yeah, it's that much difference.

A friend who does a lot of observing has a 10" as his biggest scope. He has a 6" and had an 8". After a few nights in the field with me and the 15", he sold the 8" and got a 10". Just this morning I was talking about using the 4.25", and he said "Man, after using the 15", I don't think anyone could put up with anything less than 10".

In fact I'm probably going to sell the Astroscan. If I want a travel scope I should build an ultraportable 10". I've looked through a few 24" scopes, and even THAT is very tempting, even though currently it's about $6500 for just a 24" primary mirror.

The light at our house is getting irritating. It's still pretty dark but there are a lot of car headlights, and neighbor's lights. I've thought about making some light baffles. Every time I take the scope out I wind up giving up and going inside after enough porch lights and headlights make me stand around with my eyes closed for 30 seconds until they go away. If I had some baffles I might get less fed up.