Click on image to see full size image:

Object:
M57 - The Ring Nebula
  
Date(s):
22 Jun 2013
  
Location:
 Rancho Hidalgo, NM  
Telescope:
 LX200 10" at f/10  
Mount:
 Meade SuperWedge on pier  
Camera:
 SBIG ST-11000M  
Single-Shot Color:
 No  
Luminance:
 8 5 minute images bin 1  
Red:
 8 5 minute images bin 2  
Green:
 8 5 minute images bin 2  
Blue:
 8 5 minute images bin 2  
Comments:

This was during a super-bright full moon. The ring nebula is bright enough to image reasonably even though the sky is fairly bright.

I need to re-shoot this during a new moon to see if more detail emerges.

I used successive deconvolution operations to show the internal structure of this planetary nebula.

For once, I am happy with how the stars turned out. There were no color rings around the stars that plagued me in the past. Those were caused presumably when R, G, and B images were not equally focused. What helped was that I used FocusMax to refocus whenever the filter changed.

In the past, I was trusting my calibration of the TCF-Si focuser to do temperature compensated focusing without involving FocusMax. That seemed smart at the time... I'm still not sure why that is not sufficient. I did a lot of work to determine the temperature versus steps coefficient. It seemed to be linear but there must be some factor I am not taking into account.

FocusMax is somewhat complex but pretty amazing. I can recommend it highly.