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Old 05-07-2021, 06:24 PM
RugbyRene (Rene)
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RugbyRene is offline
 
Join Date: May 2015
Location: Sydney
Posts: 352
Quote:
Originally Posted by Startrek View Post
Rene,
I’ve used the same camera and filter in my 6” and 8” newts for nearly a year now
I only see abnormal noise sometimes when conditions are less than ideal and I’m imaging with short subs ( 60 to 90 sec ) with the camera set at highest dynamic range or gain 0. Other than that the cameras performance set at highest dynamic range ( gain 0 ) cooled to -10 to -15C pushing 2 to 5 minute subs at both imaging locations , Sydney Bortle 8 and South Coast NSW Bortle 3 is almost noise free ( I usually only require a noise reduction of 2 to 3 pixels
Some details may help diagnose your issue
Camera setting ( gain offset ) ?
Cooling setting ?
Exposure lengths ?
Bortle class skies ?
Seeing conditions when this chrominance noise was apparent ?
Focal length of scope ?
Do you dither your subs ?

Seeing conditions have a significant affect on noise ( see above my experience to date )

Martin
Here's some details. This is s single frame. Yes I know noise will be reduced by stacking but to be honest there wasn't that much difference.
  • Date taken - 17 June so close to a new moon
  • Camera setting ( gain offset ) ? gain-100 offset - 50
  • Cooling setting ? -10
  • Exposure lengths ? 300sec
  • Bortle class skies ? Class 6 (Sydney)
  • Seeing conditions when this chrominance noise was apparent ? Don't know
  • Focal length of scope ? F/L550 (Esprit 100)
  • Do you dither your subs ? - yes they were dithered

Rene
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