Posts Made By: Jeff Barton

Anyone know where Celestron gets these? Celestron support says they're "unknown third party" but mine came with the scope in the original Celestron box!

I need another one so I can cut one down by 1/4" to reach focus on some wide angle 2" eyepieces.

--jb

Alberio:

I don't see the same thing with mine. Even on Vega there doesn't seem to be any false color.

I spent quite a bit of time on collimating mine and it's just about perfect. Have you checked that?

--jb

Steve:

What part of the country are you in? Perhaps a local organization can help you with this. In Dallas, TX, for example, there's a very active local group (Texas Astronomical Society) that helps with such activities.

I give local star parties (Garland, TX) the first Saturday of every month, and at times of special events (like eclipses and meteor showers). I usually set up an array of different telescopes at these. They include a Stellarvue AT1010 80mm refractor, a 6" Celestron CR150HD refractor, an 8" Celestron G8N f5 "cat" newtonian reflector and sometimes a range of "department store" scopes like an ST80 and a Meade Polaris 4.5" reflector.

This allows people to see for themselves what scopes of different types and sizes can do.

Binoculars should be among your cast, as well, because there are many objects that are far better in binoculars than in most scopes.

While I do not have a dob in my mix now, I will acquire one next year. People frequently bring them and they are wonderful scopes ... especially for DSOs.

As to comparisons with a TV 102, any of the 4" Stellarvues will be in the same range (a little color in the achromats, of course ... but not as much as you might think) but the Celestron 6" refractor will not be as sharp on bright objects or on planets unless well filtered. If you include a TV102 in your mix, then you'll have the best planet scope among those I've mentioned.

I'd heartily recommend either an AT1010 or an 85s or 78mm Blackhawk from Stellarvue for wide-field use. They will be ton sharper than a short-focus newt like the larger 8" G8N and a lot easier to transport and set up. The G8N is my favorite star party scope, however, because for its aperture it is very easy to transport and it maintains its collimation extremely well.

Email me at [email protected] if you have other questions or I can be of any other help. Also, check out my books list at the Yahoo! Group "astronomyforums" and let me know if there's a book on that list I could donate to your group.

There's also a downloadable PDF file I distribute at my star parties. You can download and copy that freely if it's of interest to you.

See the folder labeled StarGeezer (I post there as chipdatajeffb).

jb

Jim:

The non-profit organization for which I now work purchased three double-stacked SM90 scopes from Coranado about a year before Coronado was acquired by Meade. At the time, our imaging team had experience with the 40mm and 60mm Coronado scopes and wanted to move up to a system that a 2" throughput for large-chip DSLRs and CCD imagers.

We also wanted a better focuser. At the time, there was an option for a FeatherTouch focuser that replaced the standard helical focuser and accepted 2" accessories without vignetting. This required a special adapter that replaced the BF30 tube/helical focuser unit with a simpler adapter to interface with the FeatherTouch.

These setups work quite well. You can see comparison photos made through several different Coronado setups in the Gallery at our Web site (www dot 3RF dot org).

I can tell you that visually the double-stacked filters are very much better at showing surface detail than the single filters. Since I have been using them, there haven't been that many prominences for many to characterize the differences there. But the difference in views of active regions, in particular, is quite dramatic.

Adding this focuser and adapter to the Coronado scope means it will no longer fit into the standard case supplied by Coronado. To travel with this setup, you remove the focuser from the BF30/adapter tube, then unthread the BF30/adapter tube from the sliding focuser tube, and store the diagonal, focuser, and BF/30 adapter tube in a separate box.

In my opinion, another huge advantage to this setup is that it allows the use of a truly good 2" diagonal for visual use (we don't use a diagonal for imaging).

Hope this helps.

Jeff Barton