Telescope?

[Bolthead]

Thanks a bunch Patrice. While searching specs, what do I look for when I want to see what the aperture is? Is it focal ratio? I'm looking at a neat little GoScope by Orion. It's well within my budget. It has a focal ratio of f/4.3, I don't know if it's good enough or not? It's an 80mm refractor, with a bundle, tripod, can be used tabletop or tripod. The only problem is it has a focal length of 350mm.? Altazimuth mount.

I was also looking at this Orion as well. Thanks for ur patience.

 

[Patrice]

The aperture is the diameter of the mirror or objective lens. The 80 mm refractor thus has an aperture of 80mm (just over 3 inches). Divide this into the focal length and you get the speed or focal ratio of the scope. Means exactly the same as for camera lenses. Small short tube refractors in the 80 to 100 mm aperture are nice little compact scopes good for terrestrial and astronomy. It will give you nice views of the bigger clusters and won't be too bad for planetary either. Note, longer focal length refractors are usually better for planets and other bright objects, especially when dealing with achromatic refractors. You will get some purple fringing though, you'll have to spend a fair bit more money to get a refractor without this aberration (google "air spaced triplet apochromatic refractors" for a healthy dose of sticker shock). Mirror scopes are not as prone to it.

As for this one,
this Orion as well. Thanks for ur patience.
Not a bad telescope but personally I have not had a lot of luck with that type of mount. However, there are some that are exceptional but expensive, this is not one of them.

 

[Kolia]

I'm glad I found this thread !

I used my new Celestron NexStar 130SLT for the first time last night. Weee, what a treat to see Jupiter and its moons. So much details on the moon too.

This is my first telescope. I chose that one because I could use my cc miles to get it. I didn't research it much...

The computerized mount makes things so much easier to setup and use. It finds and tracks objects on its own.