Weird DSS output

[Chris85]

Hi All,
The last few times using DSS my end result has what looks like grain running diagonally across the frame. It's only just recently started to show up in my stacks, but for the life of me I can't remember changing any of my settings. I used Median and it was a stack of 7 subs with no darks or flats. See below for a crop of both the RAW straight from the camera and the output from DSS
Any ideas?
Cheers

[cometcatcher]

It's noise from the heat. Taking darks will help, but take them at the same temperature as the lights.

[Chris85]

Thanks Kevin, so would that be "dark current"? I'll have a go tonight at capturing some darks and see if that fixes it.
Cheers

[cometcatcher]

I get a bit confused between dark current and noise. Yours look like hot pixels made brighter by high temps. Darks will subtract them whatever they are.

[jjjnettie]

Definitely a Summer time problem, that type of noise. :(
In theory, if you dither it shouldn't happen.

[Chris85]

Yeah it's got me buggered Jeanette, I use dithering with BYEOS so who knows what it is. It's just only recently that I've been getting that diagonal "grain" in my stacks. Oh well just add it to the ever growing list of problems.. :screwy: