New scope on the way. :)

[admin]

Fingers crossed!

[gboulton]

Well, equipment issues (none from the new scope...my laptop wanted to be flaky) and other wharrgarbl cut into my time significantly, and I knew I had clouds rushing in. So, I switched up to something I thought I might have better luck with on less than an hour of integration, and chose M45.

• Orion ED80T CF on a CG5 Mount, with Orion SSAG and 50mm Guidescope
• BYE for session management, post in StarTools and PS CS2 *Canon EOS 450D @ ISO 800, IR filter removed
• 10 x 180" Lights, 5 x 180" Darks, 5 x 1/4000" Bias, 5 x 1/40" T-Shirt Fats w/ White LED Flashlight
• Imaged from a Red zone in Middle TN

This is the result of some hurried post last night. Honestly, with only 30 minutes of integration time, I'm probably not inclined to spend a great deal more time on post...it was really more about testing the scope than capturing the object.

I'm quite pleased with the scope. Considerably more of the dust and faint-stuff there than I'd expected for such low integration time, and a very enjoyable field of view as well. Quite happy.

Mechanically, focusing was ridiculously easy and MUCH more precise than the SCT, and the focuser locked in very nicely. Setup and takedown were WAY faster of course, thank you light weight. The CG5 is quite happy with the smaller scope, and I saw the lowest oscillation indexes I've ever seen in PHD. I don't think 10' subs will be a problem with this guy at ALL.

Optically, my only "disappointment" was the amount of field curvature present. I knew it would have some, of course, but most of the descriptions I'd seen made it sound...to me, anyway, and this is of course quite subjective...considerably less noticeable than it is. It's bad enough that StarTools won't even identify the things at the edges as stars in some cases. *heh* Admittedly, though, ST WAS able to warp them back into decent shape when I manually masked them. And, of course, a good field flattener will take care of much of that.

All things considered, an exceptional addition to my inventory, i think, and I can't WAIT to get this thing out into a dark site and have some real fun.

[admin]

That's fantastic Gordon!
The scope's FOV seems like it was made for M45.
Not a hint of chromatic aberration - very, very tight!
Slight bit of coma at the edges - got a flattener coming? Nothing the Lens module can't handle though...

[gboulton]

Thanks, Ivo!

Yes, flattener on the way. Turns out Agena Astro has the HoTech SCA on sale for $160...couldn't say no to that.

This image is pretty severely cropped...the edges show a considerable amount of curvature. Here's the top right corner from last night's unprocessed TIF, as an example:

I'd seen the curvature described in varying degrees as "noticeable" and "present, but not significant", and even one person remarked "virtually nonexistent" . Personally, I'd call that "significant" to say the least. Still..it's all subjective, so it's all good. The flattener will correct most of it, and StarTools can certainly tighten up what's left. I've fixed far worse in tracking errors.

[admin]

For an uncorrected field, that's really not too bad. It's got to be better than your SCT uncorrected, whose design is notorious for all sorts of funkiness in the corners. I originally made the Repair module's 'Redistribute' algorithm for a user with SCT but w/o corrector - stars were unrecognizable as such!
Excellent purchase & as my late grandmother would say about a major new purchase; "use it in good health!"

[gboulton]

Right now, I'd just like to use it in dark skies!

Thanks for the input...oddly, I think it's WORSE than the SCT was, but that could just be me.

Crop from the corner of a stack of M2 I did last year.



Who knows...either way, as I said...flattener and ST should definitely take care of thing...and needing a flattener for a refractor isn't unusual at all, so I'm certainly not upset.

[admin]

Wow... That's really good for an SCT design!

This is the SCT coma I was trying to fix with the Repair module;

[gboulton]

That's not coma...there's a wormhole nearby distorting those poor blobs of light!

[admin]

That's not coma...there's a wormhole nearby distorting those poor blobs of light!

Yeah, that was kind of a challenge when he asked/showed me...