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Old 27-07-2009, 05:33 PM
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multiweb (Marc)
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Join Date: Oct 2007
Location: Hinchinbrook
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Quote:
Originally Posted by kinetic View Post
It could be amp glow showing? A downfall with modded webcams
with a lower dynamic range. Not sure if the QHY8 would suffer from
this.
One way to prove that would be to do a similar stretch on a 'light'
frame.

Steve
No there's no Amp Glow problem with the QHY8. As Theo pointed out you can switch this on/off in the capture software.

Quote:
Originally Posted by Gama View Post
The QHY-8 does have Amp glow, but has the ability to disable it in the setup when you connect to it. I always have it set to ON.


Marc, you may want to ask Qiu what he thinks about your issue, maybe software or similar..

Theo
Ok, I think everybody's getting confused here. Nothing's wrong with the camera or the software used. The dark I posted is a stack of 40 x 0.8s. Call it a bias if you want. The ADU level on the bright part of the frame and the top is approx 1044, the darker parts are 1021 ADU. So the image is scaled as a 16 bit TIFF file from the raw FITS file with a range of 23 ADU which is minuscule. If I load Doug's dark frame and measure it (although converted from JPEG to TIFF) they show a range of approx 240ADU between the darkest pixel and the lightest.

My point was that scaling a picture can make it look like anything you want. No more no less.
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