View Single Post
  #36  
Old 02-06-2014, 01:38 PM
pvelez's Avatar
pvelez (Pete)
Registered User

pvelez is offline
 
Join Date: Aug 2006
Location: Sydney
Posts: 1,250
Quote:
Originally Posted by RickS View Post
Hi Pete,

Dave has been pretty busy lately so I suspect you won't hear back from him soon. I also suspect he won't know the answer to your question. You should ask SBIG and/or poke around the extra data in the frame to figure out where the overscan data lies. On my 16803 camera (Apogee U16M) there is a set of 10 columns at the far right of the frame that do the trick but the SBIG driver will almost certainly map things differently.

Cheers,
Rick.
Thanks Rick

I think it was the discussion about real vs dummy overscan that threw me. I can access my obs PC from work so I'm playing with this as a I type.

Looking at a 1200 second dark, I have a dark border to the right and bottom of the frame. However at the right side, there is a brighter line (several pixels wide) between what appears to be the edge of the image and the dark border. I wonder if this is the readout channel for the chip. I've posted a pic.

Interestingly, I have no dark border at the base of a bias frame, only to the right. Also attach a pic.

How do I distinguish the real overscan from the dummy overscan?


Quote:
Originally Posted by troypiggo View Post
My QSI583 (Kodak KAF 8300 sensor) has 279 columns on the right. Spoke to QSI's Kevin Nelson about it, and he recommended just using the right-most 100-150 columns. So it varies from sensor to sensor, and possibly(?) camera manufacturer to manufacturer.
Sadly, SBIG are less forthcoming - though there may be something deep in the bowels of the SBIG site - off to do some digging now

Pete
Attached Thumbnails
Click for full-size image (screenshot.jpg)
184.7 KB28 views
Reply With Quote