Posts Made By: Larry Durst

I received a Q453HR from CCD-Labs ...and you can't believe the thunder storms we're having! So rather than shooting I'm, well, hitting up the Groups for advice on how my approach might differ from my prior experience with a monochrome camera (MX716).

I have drivers all installed on both Nebulosity (bundled with the camera, new software to me) and AstroArt3 (what I've been using for years with my last camera ). Would probably prefer AA3 since I'm used to it, but certainly don't mind trying out Nebulosity either.

I see the recommendation with Nebulosity is to shoot RAW, but don't see such options in AA3--maybe it's the default or maybe it doesn't matter. I do have the offsets for both set to give me around 300-400 min count on a bias frame.

Anyway, as you can see, I'm just wondering if anyone has any advice on shooting my first images with this camera. (Will be using my WO Zenithstar 66SD with 0.8 focal reducer.)

Thanks,
Larry

All,
It's been a while since I've posted as I've been camera-less for a while--sold everything but my trustly LX90 8". Have been looking at the great work, however, which just feeds the itch to justify some new purchases.

I previously owned--and loved--an SX MX716 with RGB and Ha filters. Most of my shooting was through a piggybacked WO Zenithstar 66 SD, guiding through the LX90 with a DSI Pro. Setup worked great. Getting back into it, I'm pretty sold on OSC. I find Dietmar's arguments and comparisons helpful and convincing.

My budget is under $2000. My decision boils down to one of the newer generation of multi-pixel Sony-based OSC such as Orion or QHY, used SX H9C, or used SBIG ST2000XCM. I am really sold on self-guiding SBIG--aligning two scopes with each other and focusing two cameras is a real time-eater each night. I'm interested in galaxies with the LX90 at 6.3, so wouldn't have to buy a small refractor.

On the other hand, those other cameras are much larger (except the H9C). And, with their Sony chips, not shooting darks would certainly make up for the time of setting up a guidescope.

So, smaller FOV and images (drawback?) with self-guiding (yeah!) but the apparent need to shoot darks (ugh!) versus big chip and no darks (yeah!) but two scope set up (ugh!).

Thanks for letting me vent my long-winded indeciveness. Any opinions appreciated.

Larry

Ivan,
It could well be two different problems. The round contrast is probably vignetting. I think (despite my middle-aged eyes) I see elongation on your stars in the corners on the edges, all pointing to the center. Also, the more you stretch the more you'll see the uneven lighting occur. I get it with my 3.3 FR on my 8" SCT. Plus you're trying to cover a very large chip on a DSLR. Have you tried to shoot flats? It's pretty simple to do and can work wonders. Some software also enables you to do artificial flats (eg: AstroArt). The lower black bar seems to be more of an obstruction. Anyway, that's my guess.
Hope it helps,
Larry Durst

My turn, Cal. Great shots. Both of these images have amazing detail. What are you shooting with? I've tried a couple of wide field with camera lenses, but haven't licked the scope/lens alignment yet. (Any collimation hints?)
Again, beautiful work.
Larry

Just stunning, Larry. Can't wait to see more.
Larry Durst

Don,
Very nice shot--you did indeed bring out lots of detail. Question: is the image cropped? Or is that your entire FOV at f/3.3?
Larry Durst

Very beautiful, Tom. Amazing what even short exposures can find in M42.
Larry

Your hard work definitely paid off. Very rich and detailed. Thanks for sharing this excellent adventure.
Larry Durst

Looks like it was well worth lugging the gear. I don't know where to look: M42 or the Running Man. Great job handling the Trapezium, too.
Larry Durst

Hi James,
It's a narrowband filter that isolates and lets pass just light emanating from Hydrogen Alpha, a thin slice of the red spectrum. Emission nebula are exceedingly rich in this area--it's what gives them their glow--so you see Ha filters used on these targets, often replacing the luminance. They come in both 1-1/4 and 2-inch sizes, just like other RGB, LPR and visual color filters. (I've never used a solar filter, so can't speak to them.)I used one for the first time the other night on B33 (or IC434) and can tell you this: without the filter I couldn't see the Horsehead on my monitor at all, even after a 30 or 45-second integration. With the filter in place--wow!--there it was in great detail. (Image posted previously on this list.) After just one use I already feel like it's a must-have item in my arsenal.
I hope this clarifies more than confuses (and that I haven't botched the science too badly).
Have fun,
Larry Durst