subtle processing rings

[Nocturnal]

Cleon,

looks like you have significant drift from sub to sub. I imagine PI reports on the image shifts but I don't know for sure. I use this technique:

http://deepskystacker.wikispaces.com/Measuring+differential+flexure

In any case, with enough subs and sigma type stacking you should be able to reduce at least the appearance of the hot pixel streaks. If your drift isn't enough to make the hot pixels stand out enough for sigma stacking to eliminate them you could add dithering to your capture process. I generally recommend getting differential flexure under control first but under some conditions it can help improve image quality because it randomizes the streaks, making them less obvious.

[Cleon_Wells]

Sander, thanks for the link, I'll try to tighten up the guide scope/mounting tonight and see if anything changes. The total time for the 43 subs = 107.5 min, with 2 min per sub with .5 minutes between the subs. Here's and image of my setup with a lot of places for flexure.
Cleon