#1  
Old 21-12-2008, 09:54 PM
RobF's Avatar
RobF (Rob)
Mostly harmless...

RobF is offline
 
Join Date: Jul 2008
Location: Brisbane, Australia
Posts: 5,526
In camera noise reduction and bias frames

I'm sure I haven't really got my head around what bias frames are for, so.......

What happens if I use ICNR - is it still a good idea to shoot some bias frames at fastest shutter speed and use these during image processing/stacking?
Reply With Quote
  #2  
Old 21-12-2008, 10:18 PM
Matty P's Avatar
Matty P (Matt)
Star Struck

Matty P is offline
 
Join Date: Nov 2007
Location: Canberra
Posts: 2,797
Rob, most of the time you can get away with not shooting Bias (Offset) frames if you take dark frames, because the Bias is included and removed in the dark frames. But if you take flat frames and don't subtract darks from them, you will need to take Bias frames and subtract them.

ICNR is exactly like taking seperate dark frames except it is automatically removed in the camera meaning you will not need to take Bias frames unless you are not taking seperate Darks for your Flats.

Hope this makes sense.

Reply With Quote
  #3  
Old 21-12-2008, 10:20 PM
Terry B's Avatar
Terry B
Country living & viewing

Terry B is offline
 
Join Date: Mar 2006
Location: Armidale
Posts: 2,764
There is no need.
The only time bias frames are needed is if you are scaling your darks. With ICNR there is no scaling and the bias will be removed with the automatic dark frame which should have the same bias.
Reply With Quote
  #4  
Old 23-12-2008, 01:03 AM
RobF's Avatar
RobF (Rob)
Mostly harmless...

RobF is offline
 
Join Date: Jul 2008
Location: Brisbane, Australia
Posts: 5,526
Many thanks guys. Sounds like I'll rarely need to mess with bias frames then. Try to shoot relevant darks for each session, especially as temp can vary quite a bit in Brissy.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 07:37 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Advertisement
Lunatico Astronomical
Advertisement
EQ8-R
Advertisement
Star Adventurer
Advertisement
Celestron RASA
Advertisement
Bintel
Advertisement
Testar
Advertisement
Astromechanics
Advertisement
Astronomy and Electronics Centre
Advertisement