--- hanksdc@plug.org wrote:
Since I've not got much experience with 'nice' scopes, what should I be looking for?
The best advice I could give would be to attend some star-parties, and look through other people's scopes. This allows you to make a decision BEFORE you spend any money. Most people are too happy to let you look through their telescopes. Also, most reputable dealers will give you return priveliges if the scope you actually buy turns out to be a dud.
Is there something I'll see that will indicate that the scope is vignetting?
This isn't a precise, exact answer, but when you look through the focuser without an eyepiece, with your eyeball dead-center, you should be able to see the entire primary mirror without moving your eye around. If the edge of the mirror isn't visible, there is a probable vignetting condition.
Or will the image just not be as detailed as it could be were the scope using all of its mirror?
Not a loss of detail, but a loss of brightness that you can't detect, because you don't usually have a non-vignetted comparison telescope side-by-side.
What things might I see to indicate that the mirror is not fully parabolized?
Short of a Foucault or Ronchi test (performed on the optical bench or with a special Ronchi "eyepiece"), the image will be soft at high powers, when known telescopes of high-quality are giving sharp, detailed images at the same time (to eliminate poor atmospheric conditions as a variable).
I'll be testing it out tonight, so of course that will probably be the real test--if it's enjoyable to use.
Good luck, Dan, let us know what you find out. Chuck __________________________________________________ Do You Yahoo!? Yahoo! Health - your guide to health and wellness http://health.yahoo.com