what are these caused by?

[Daniel-K]

just done a quick process and these dots have appeared any know what they are caused by ?

[JamesF]

Odd. It looks like the same pattern each time though? At what point in the processing can you first see them?

James

[Steve Ward]

They are hot pixels , you didn't take any dark frames to eliminate them I'm guessing.

Steve.

[Stephen]

They are hot pixels , you didn't take any dark frames to eliminate them I'm guessing.

Steve.

Not convinced to be honest, seen a lot of hot pixels, but never similar groups/patterns like that.

As per James, when do you first see them?

[Steve Ward]

The grouping is identical , leads me to say that the frames weren't shot with accurate tracking , DSS has aligned the stars and therefore the pixels appear to have moved around.

I get the same thing if tracking's off , usually a line of hotties where the scope has drifted , that's what convinced me to start taking dark frames........

Steve.

[davew]

They look just like hot pixels to me. I've seen the effect when dithering and the SD mask hasn't worked.

Is this a stack of 10 subs ? Does each sub show 1 hot pixel in that area ? Which stacking program ?

If it's not hot pixels then I've no idea.

Dave.

Posted at the same time SD mask in Maxim should work with 10 subs but pixel rejection in DSS may not.

[Stephen]

The grouping is identical , leads me to say that the frames weren't shot with accurate tracking , DSS has aligned the stars and therefore the pixels appear to have moved around.

Very feasible I concede

[Daniel-K]

i didnt use DSS i used nebulosity3 there not the snigle subs, as for hot pixels the cameras cooled ?? hummm...

[Stephen]

i didnt use DSS i used nebulosity3 there not the snigle subs, as for hot pixels the cameras cooled ?? hummm...

Cooling does not remove all hot pixels, sorry

My Atik at -5 to -10 still has 5 or so hot pixels.

I honestly find DSS to do a better job on hot pixels than Nebulosity, but I might be missing a step in my processing with Neb.

[Daniel-K]

i cant get DSS to stack my files that i have captured with neb3?

[Stephen]

Check out the Nebulosity manual, it discusses bad pixel mapping

[Daniel-K]

working my through it, this is the first bit of data i have had to work with

[Steve Ward]

I suppose you could have captured the Federation Formation Flying Team going through their new routine...............

[sologuitarist61]

Very strange as they are all the same pattern, as has been said already.

I think the only answer is that you have the first photograph of a fleet of alien battle cruisers en-route to Earth. God help us all!!

(Sorry to not be more constructive in my answer)