In spite of poor sky conditions, I wanted to try a few new things, because the weather forecast is like a depression for quite a while.
1. An aperture ring (from
https://www.liquidart-shop.at/) onto the Newton mirror
2. Multi-star guiding in PHD2 Dev3
3. Dithering with digiCamControl and PHD2
No more than 30 somehow usable frames, total of 15 minutes, were left for this test. Several times, PHD2 lost the guide stars as clouds rolled in causing guiding errors and notable image shifts. The resulting integration time is everything else but sufficient in that I cropped the Running Man also because of coma at the top left corner of the image, probably tilt. Though this was not at all the ideal evening for a test:
1. The aperture ring eliminated the unwanted star spikes almost completely (Ex.: 44 Ori bottom right). Unstable air caused some diffractions, this ignored, the stars are looking great. A prior quick test on the brightest star Sirius with a single frame looked very good, too.
2. Multi-star guiding is way more precise than guiding with a single star, almost revolutionary. Stars would be rounder under clear sky conditions, see Rev B.
3. Dithering seemed to work well, I hardly had noise in the images and no traces of sensor scratches (no calibration frames used).
Though some homework remains (mainly for the weather), this looks hopeful for future DSO, in particular galaxy, images with the 6"/F5 Newtonian.
Opinions and suggestions are most welcome.
Cheers and please stay safe!
Robert
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