The Start of a Mosaic

It's been kind of wild since the last post. We've had many days of air quality alerts, most of which have been for excessive surface ozone, a byproduct of smoke and sunlight and "normal" air pollution. Smoke at times thickened to concentrations similar to what was seen earlier on the East Coast. It wasn't healthy at all; hospitals reported a surge of people with breathing difficulty.

The air quality did improve for a bit and I was able to get out and do a little imaging. In fact, I managed to start one of my learning projects!

One item on my to-image list is a mosaic of the Veil Nebula that spans both the east and west sides. The Veil isn't immense like Barnard's Loop, but it's large enough to require something like a 250mm lens to fit it all in a single frame. My FSQ-106 has a focal length of 530mm and it really needs something like a 2x3 mosaic to encompass the Veil. That's 6 frames, and at about 2 hours exposure time for each it will make a good summertime project that could last into September.

Despite the ever-present smoke I was able to collect the data for subframe 1 which includes most of the East Veil (NGC 6992) and the Network Nebula (NGC 6995): left click the image below, then right click the enlarged image and choose "Open Image in New Tab" to see the image at 1/2 scale:

 

 

For fun, here's a try at a starless version using StarNet2 in PixInsight:

 

This is LRGB with all exposures 120s, L = 20 lights, R = 11, G = 12, and B = 12.

I think I dark-clipped this a little in my processing haste, but it will get another processing eventually.  Here it is tucked into its place in the eventual mosaic:

 

6995 is in the overlap area between subframes 1 and 3. The next target will be subframe 3 to complete the Eastern Veil and give me some practice using PixInsight to create a mosaic.

Some other tidbits from this too-rare night of imaging:

• The QHY-5II guide scope was flawless with over two hours of guiding without a single disconnect. It really does need USB3, it seems. 
• Not only that, but tracking errors were limited to 2 frames in 58. A rate of 1 bad frame in 29 is a lot better than the 1 in 6 that I had experienced earlier this year.
  
• NINA's Advanced Sequencer finished subframe 1 and started subframe 3 imaging without any attention on my part. This was the first time I had tried this. I wasn't willing to do another two to 3 hours of imaging so I reluctantly shut it down at that point.
• More NINA: Its mosaic feature is nicely integrated into the Framing Assistant and sets up the Advanced Sequencer for all the subframes with simplicity.
• Even More NINA: If you want to use the Framing Assistant with images while you're someplace without Internet, go to the NINA download page and grab the Offline Sky Map Cache file (2 GB) It replaces the existing cache folder AppData >  Local > NINA > Framing Assistant Cache. Don't forget to change the Framing Assistant Screen's Image Source setting to Offline Sky Map! Incidentally, installing this allows you to zoom out and use Framing Assistant like a (rather strange) planetarium.
• I seem to have gotten the hang of PI Deconvolution. I don't know why it was so temperamental before, but the key seems to be in the Deringing settings. A Global dark of 0.03 to 0.02 seems to work well, with Global bright typically between zero and 1/2 of Global dark.