Ad Astra Observatory

The other morning when I was awakened at 5am by sprinklers, I noticed that Jupiter was past meridian (meaning so was Sagittarius, but it was too light for me to see it). This means that if I did a really heroic night of astronomy, I could probably post an early image of the summer nebulae!

I hate it when I do that, though — then I have nothing to shoot in August. (:

Orion’s new planetary camera, pros and cons.
Apparently Orion ships Max Essentials with the S^4 because K3CCDTools won’t read the camera. Disappointing, but the K3 “free lunch” was too nice to last. Works like a champ with my NexImage, though.

With the 2000mm SCT and stacked 2x barlows, Saturn is almost too big to fit in the FOV of the NexImage at 640×480. A good reason to bump to the Orion cam, which does 1280×1024.

I am frankly shocked that K3 hasn’t stepped up to working with the Orion camera. Makes me wonder what QHY is doing in firmware… hmmm…

Planetary processing tips:
I usually aim for the “max” value in the histogram to read a little under 128 (the halfway point), because images brighten some when you stack them. In K3, there’s a nice histogram meter that helps with this.

Note: You have to do this while focusing/shooting, not while processing.

I need to figure out a good process to fix any AVI’s that have gone south. Apparently, the solution is on the K3Tools page along with all the software tools to fix these problems.

I’ll have to go search his pages to find this. I hate it when I run into processing problems on my planetary stuff. It eats so much disk space that I can’t afford to keep the .avi’s around for long.

Webcam autoguiding
Exposure length
I have been sniffing around the edges of trying to use a webcam for guiding. The main problem, as I see it, is that my ST-4 (which works awesome) needs 0.5sec exposures to find guidestars, and I usually have to guide on mag 4 or brighter stars as it is. With a webcam, the longest exposure is usually 0.2sec, so I might have to guide on brighter stars.

Mechanics
Also, I’m not sure exactly how the guide control would work. I’d have some kind of software to read the images coming in off the cam (MaxDSLR knows how to do this), but then I would need to get those commands to the mount somehow. Now that I have a Gemini mount, I can play around with mount control via ASCOM. But otherwise, if I wanted to use the autoguider port on the mount, I’d need a GPUSB or something.

A webcam + ASCOM-controlled mount would also save me a few cables — right now, I use 2xUSB-to-serial to connect the ST-4 and mount to the computer, plus autoguider, power, and CCD cables from the ST-4 to various points around the mount. I would still have the 2 USB connections to the computer, but I’d save the other 3, since the camera is powered by the same cable that it transmits its images over, and since the mount would not need anything plugged into the autoguider port.

Adding a GPUSB to the mix would still save me a cable or two, but would kind of defeat the purpose of this svelte setup.

I’m also considering a tandem rig. I think that would help some of the balance problems I’ve had. Probably won’t happen soon. Pumpkin is basically a finder anyway.

Focusing
Using a webcam for a guider would really speed up focusing the guider, since it can stream images in realtime. In theory, one could find perfect focus in 30sec every time. I can never get perfect focus in 30sec. It always takes sooo looong for the focuser to move since I have to move it with the buttons and not just twirl the dial until I’m close… *snif* I miss my manual focuser, just a little.

An alternative

The new Orion autoguider ($250 as of this writing) is an interesting idea — It would have the flexibility to do either autoguider port (via its integral autoguider output) or let the computer do ASCOM. That’s a serious contender for ST-4 replacement.

I have to say that it’s mostly my emotional connection to the ST-4 that keeps it around at this point. Plus, the laughable concept that I might run it standalone at some point. The ST-4 has been a real workhorse for me, and I’d hate to let it go. But the Orion autoguider is really tickling the back of my brain.