View Single Post
  #2  
Old 18-10-2013, 06:46 AM
naskies's Avatar
naskies (Dave)
Registered User

naskies is offline
 
Join Date: Jul 2011
Location: Brisbane
Posts: 1,865
I have the same camera - master dark frames will always give you better results.

Just like light frames, dark frames also have noise (random fluctuations in the dark noise, cosmic rays, radiation hits, etc). If you only subtract a single dark frame, then you effectively add the noise of the dark frame to your light frames. Worse still - I believe that Maxim re-uses dark frames for consecutive shots, so you won't be cancelling out that noise with multiple light frames.

I find that stacking at least 10 darks gives me a noticeable improvement over a single dark frame, though I usually try to aim for 30+. You'll get better results from shooting master dark frames for each sub duration that you use (unless you go to the hassle of using overscan calibration in PixInSight).

That said, the 8300 chips are very low noise in 1x1 binning so if you're shooting bright targets such as Orion Nebula and not stretching your subs particularly hard you may not even notice much/any difference between a single dark vs a master dark.
Reply With Quote