A Guide to the Sky, Telescopes, and Telescope Programs
Which scope to buy?
There is no easy answer to that.
My wife asked me once, "Why do you need so many telescopes?" "Because they all do something different." Each type has a different strength.
For a Library Program, I recommended the Orion XT6i Starblast, a computerized "table" dobsonian. It's a good sturdy scope for beginners and it's portable.
If you were to ask me the best scope for a beginner serious about astronomy looking for a capable high-value scope, I'd recommend an Orion XT8i Intelliscope. It's big enough to see "faint fuzzies" (a.k.a. Deep Sky Objects) and able to handle the high magnifications you want for Jupiter and Saturn (the Starblast is a bit small for that).
Mounts for Beginners
Mounts are Equatorial or Altitude-Azimuth (Alt-Az)
Observing with Equatorial mounts can be a little complicated; they're good for astrophotography.
Alt-Az mounts essentially have an up-down axius (Altitude) and a left-right axis (Azimuth). They're easy to point.
Another division in non-motorized Alt-Az mounts is whether they have gearing for adjusting the pointing. These "slow motion controls" are very useful at high power, but unless you have an expensive apochromatic, you won't be at high power. Knobs and gears will also confuse your guests. Explore Scientific's Twilight Mount retails at under $200 and has these controls.
Some mounts such as Televue's Panoramic and William Optics EZ Touch do not have the "slow motion controls". You simply point the scope where you want. They are very easy to use. Both are more expensive than the Twilight mentioned above. Televue is something of a Cadillac brand; the Panoramic retails at almost $600.
What's a Window Scope? It's a scope that sits in that room in a house or apartment that has a view.
Here's a good summary of How to Choose a Telescope. I'm going to refine that to focus on Window Telescopes.
So if money is no object, the best-performing, short, daytime and night time refractor would be a "fast" apochromatic refractor. They provide wide fields and have color-correcting lenses that can handle very high magnification (50x/inch of aperture). They are the most versatile scopes, but are expensive.
A wide field "fast" (meaning it has a low focal length/aperture ratio, like in camera lenses) achromatic or "Enhanced Dispersion" (ED) refractor is what you should look for. Achromatic refractors are the least expensive, but they do not handle high magnification well. Basically that means that you can't crank up the magnification on Jupiter and Saturn without colors tending to bleed together. You will not be able to "split" as many double stars as an expensive refractor The moon will be excellent as well as the fainter deep sky objects. Aperture helps. I love my fast 120mm achromatic refractor with its fast f5 600mm focal length. I cannot exceed 200x for Jupiter and Saturn, but everything else works nicely. New, the Orion 120 is around $300. Explore Scientific has an equivalent. Explore Scientific has a 100mm with a dual-speed focuser for $399.
My wife recently told me that a mutual friend was looking for recommendations for a telescope for their new house. Oh, he's going to want a high-quality window scope. I'm used to providing recommendations for really tight budgets, so it's nice opportunity to make some recommendations for some more robust and higher quality equipment.
The telescope recommendation will be essentially be based on what he wants to spend. There are some really pretty (and very functional) ED and "APO" scopes in the $1000 range. Pretty counts on an window scope. Perhaps one of the prettiest is the Televue Renaissance, which is not only beautiful in brass, but it's highly respected for its optical excellence.
I do have a strong preference on mounts, though. I like a balanced alt-az without slow motion controls. By balanced, I mean that the Center of Gravity of the scope is in-line with the altitude axis of the mount. Mounts where the scope sits on top of the mount generally require friction clutches to keep them from falling over the front or back of the mount. They then pretty much require slow motion knobs.
The Televue Panoramic and Gibraltar mounts have a saddle that the telescope sits on. The scope and the alt axis become close to coincident. They are intuitive and effortless to use.
I can also go with a single scope or replace the refractor with my hydrogen-alpha solar scope. Putting a white-light solar filter on the C8, gives me filaments and flares on one side and great sunspot detail on the other.
Questions or comments? Email:Jeff Martin