Surfin' google on scopes I came across this web link on a homebrew scope,

Planet scope

What can one see when viewing the planets at 250 to 500X?

Is building a scope fun?

Try this link to get a feel for what will be visible at different magnifications.

Of course there are plenty of variables that can impact what you will actually be able to see, not least being your own visual acuity and experience.

http://www.adelaideoptical.com.au/essays/showview.html



(Before embarking on building your own scope it may be well worth exploring the wealth of material on the net. Here is a good place to start:

http://www.starastronomy.org/TelescopeMaking/WebRing/

a few dead links though)

many ATMs swear by Richard Berry's book:

http://www.wvi.com/~rberry/mybooks/mybooks.htm


Read what Jeff Verona has to say on building a telescope

http://www.cloudynights.com/howto/atm.htm

It all depends on your carpentry or metal working skills. Me, well I have changed a light bulb once -I think -so I have started really small. So far, I have built a 70 mm square tube refractor (which pulls in decent but not great images) and am building a 3 inch reflector as sort of warm up exercises before embarking on a 10 inch truss type Dobsonian my longer term goal, based on Barry Leger's design.

Yes it is fun but it is a hobby within a hobby. If you want to get started observing quickly, go out and buy a commercial scope. It will probably be a lot cheaper and you can be out tonight.

Miles,
I gotta agree with seeker that building a scope now a days really depends on the person building it...it's not for everyone. Much of it really depends on how deeply you want to get into it as well. If for example your looking to grind your own mirror (pushing glass), your can be talking a lot of hard work and frustration...especially if you don't have someone expereineced to show you how to do it correctly. Definatly do more research before you start buying the parts and materials and decide if it's really right for you to do. Now a days there's no real economical advantage to doing it yourself...it costs nearly as much to build one as it does to buy one and you can get a pretty decent entry level scope for around or under $500.

As to what you can see when viewing planets 250 to 500x, I really don't think you'd see much more then a fuzzy out of focus blur with just about any scope at 500x. The practical limit for mag with most scopes is between 200x and 300x (depending on the size of the scope) and thats on a really really clear and still night! The Earths atmosphere limits the amount of magnification you can actually use with any given scope. What it really comes down to is...and I'm sure that many people here will agree with this, it's not about "power" it's about what you can actually see at any given power and that comes down to aperature...the bigger the better. If your primary interest is planets, then you don't really need a "huge" scope...even with my crappy little 60mm Bushnell I could still clearly see the rings of Saturn and the bands around Jupiter (note: I have replaced the focuser on this scope to use standard 1 1/4" eye pieces, not those crappy department store .96 pieces of junk). Something like my 127mm/5in Orion Mak has a really splendid view of the planets, but even with that, I don't usually have the mag much over 125x (scope is 1540mm focal length and I use a 25mm eye piece with a 2x Barlow...the math works out to 123.2 magnification). This combo usually makes for some pretty nice seeing .

Anyways, good luck!
Bright Blessings & Gentle Breezes,
Jim

Point to be made here; unless you have a large objective lens, a lot of magnification is going to result in a blurry image. Empty magnification. A lot of interesting deep space objects can be seen with low magnification, large objective lens (or large mirror).

As was pointed out, atmospheric conditions can wreck havoc with some observations. You don't want to try and watch something interesting (say Jupiter or Saturn) when it is near the horizon. You will be looking through far too much turbulence. Also, if you are near a city (or any area with a lot of lights), the background light from atmospheric haze will reduce the image contrast.

I had, years ago, wanted to build a telescope. It would take a lot of patience and you'd want someone to guide you if you were to grind a mirror. Compared to purchasing a ready-made telescope, you'll be likely working for the equivalent of 30 cents per hour :P


Best regards from Rochester, NY
Jim