Atik 383L+mono -- Image Gradient

[topboxman]

Very nice image!!!

You have the same guiding setup as mine. See my signature. OAG is the best way to get round stars with SCT scopes.

Peter

[niteman1946]

Thanks Peter.  Appreciate the comments and suggestions.

I'm really pleased how well all the equipment works together.   And yes, stars got much rounder with the OAG.

Mark

[niteman1946]

Closure ---- Here's my post from the Atik forum.

Just to close this loop, I believe that the fix is in. 
Joel Short from another post had experienced similar problems and had solved them by going to longer flat exposures (I believe to 3 seconds).
Thanks to his encouragement and Peter's (Topboxman), I lengthened my subs to 5 seconds (if a little is good, more is better).
I also used the Tee shirt technique and shot during the daylight.  This is sooooooo much easier than doing dusk shots.  Here I easily kept the center value of the flat subs around 31k ADU.
The Flare (at least for now) is gone.

Thanks again,

Mark

[Euan]

Mark, I've done some testing on this see here: http://photonjunkie.com/2011/09/01/atik-383l-flat-frame-exposure-testing/

[niteman1946]

This is the sort of information Atik should be providing to its community, rather than letting the users stumble around.

Good stuff Euan, you might want to post this on their forum.

Mark

[topboxman]

Atik is not the only company with short exposures issues when taking flats. Any camera with mechanical shutter will have the same issues. It's pretty well known and has been discussed often at Cloudy Nights forum.

Peter