Query about DSS - is this possible?

[Welrod50]

All, I've had a thought. Now I may be way off or not, but if anyone can chip in I would appreciate it.....

Is it plausable to shoot say 200 iso Darks and Bias to create a clean master dark/bias and then use this with higher iso lights to get a cleaner final image?

I have taken the opportunity this last week to shoot a load of darks, flats and bias frames at differing iso values and all at around 8 degrees centigrade - a little warmer than I would like, but short of leaving the camera outdoors this is the best I can muster under the circumstances.

Any thoughts?

Thanks for looking

[Photosbykev]

You need to match the darks so they are taken at the same iso and exposure time as the lights and just as important at a similar temperature.

Bias frames at the same iso and flats need to taken without altering the optical train so that the focus and camera orientation are the same

[Welrod50]

Hi Kev and yes I've done this, taking 30 second darks and bias to match the subs I take. I tend to use 30 seconds ( or less) as there is no trailing at all and using mirror lock with the camera means almost all my subs ar ok too.

[Welrod50]

_{Oh and another thing, I don't need to worry about DFS either as I'm not using bulb mode. That said, does anyone know just how much noisier images might be if I did do some 2 minute subs and turned dark frame subtraction off in the camera's debug menu?}

_Cheers