A Tale of Two Telescopes -- AWB OneSky 130 and Celestron AstroMaster 102AZ

Here is the quick summary: Both of these telescopes are made by Celestron; both are made in China; both give almost identical views of the night sky. The AWB OneSky costs $250, and a big chunk of that goes to support the outreach activities of Astronomers Without Borders. The Celestron AstroMaster 102AZ costs $275. (The scope I actually have is the NexStar SLT 102, but I modified it to remove all the computerization so it is similar to the Astromaster 102AZ.) The AWB OneSky is slightly better overall for astronomy; the Astromaster is excellent for both astronomical and terrestrial viewing.

For the time being, I own both scopes and I think I'll hold onto them both. I slightly prefer the OneSky for astronomy and greatly prefer the AstroMaster for bird watching or scanning the distant lake activity.

Both scopes are so good that I rarely break out my 8" Dob even though I know I'll get a far better view of planets and deep sky objects using it. Often, ease of use wins the night!

The Nitty, Gritty Details

Both scopes have the same 650 - 660mm focal length. One might at first think that a 130mm objective mirror would out-perform a 102mm refractor lens, but the large secondary mirror on the OneSky means that both scopes collect about the same amount of light. Both seem equally sharp. I really see no significance difference between performance either at low power (26x magnification) or at high power (110x magnification). When using the same lenses in each scope, I get about the same viewing.

The red-dot finder is mounted toward the front of the AWB OneSky while it is mounted toward the back of the AstroMaster. This makes a considerable difference. With the OneSky it is always relatively easy to tip one's head in a good position for looking through the finder without having to get out of the viewing chair. With the AstroMaster you have to choose between comfort viewing objects low on the horizon or comfort with objects up toward the zenith. You can, of course, adjust the length of the tripod legs, but that's an extra step and hardship in dark sky viewing. I think the AWB Onesky has the edge in ergonomics.

That edge is given back (and more) if one wishes to use the scope for terrestrial viewing. You can do it with the OneSky, but it's never going to be a viable option for bird-watching. The AstroMaster soars ahead as a terrestrial scope. You can even look at insects on wildflowers 30 feet from you door!

Extras

You'll need an observing chair or stool for comfort when using either scope. I've purchased a three-legged stool like this one:

If you buy the Astromaster, a light observing chair is the only additional expense. If you buy the AWB OneSky, you will also need a small table upon which to set the telescope. You can make one for free by cutting down the shipping box as I have done in the images below. Note that I have strategically reinforced the inside of the box with additional cardboard, I have created four mini-legs to raise the box off the ground by about an inch, and I have used plenty of packing tape and Gorilla tape whenever the mood struck me! The box now serves to hold the scope as I carry it around the yard and is also sturdy enough in use to damp eyepiece vibrations quickly. If I want the box to last longer, I'll probably cover it with water-resistant wallpaper.