Imaging with Dither

[Simon Hicks]

Fabio, Georg,

The cropped image is not only cropped, it is also rotated by about -80 degrees (i.e. anticlockwise) with respect to the uncropped image.

So Fabio, if you are seeing slight trailing from top left to bottom right in the uncropped/rotated image....then this should translate into trailing from bottom left to top right in the cropped/rotated image. But that's not what is seen. Strange.

Cheers
         Simon

[dhalliday]

Sorry,...I was tied up enjoying some clear sky...!!
Thanks to you all for looking...sorry my images are so confusing...
Some were taken on different nites,after meridian flips,etc...

I have remounted my guidescope DIRECTLY on my VC200L so maybe flex will be less...(I was using a home made twin mount prior...)
I still have not learned to drift align either...

Its the frame to frame movement that is puzzling....
The mirror in this scope is fixed...it is NOT the problem...
Having said that maybe the camera moves a bit,frame to frame...It "wiggles" a bit when attached...
ANYWAYS...by playing around in the "Kappa" settings in DSS I can eliminate 95% of the streaking...
I still have not heard from a pro what the best system for dithering between shots is...
I tried Nebulosity....do not like the interface much...

Any other suggestion  
PS Here is a version of M97 from the other nite...Streaking was terrible until I used "Kappa clipping" (lite frames) in DSS;

http://www.flickr.com/photos/daveh56/4101012523/sizes/l/

Dave

[Daan]

I know this is a very old topic but since I have the same issue on some of my images I wonder if there is nowadays a solution in PI to "fix this. In PI I cannot get a good stack while when I stack in DSS the output file is much better.