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Re: Photon Transfer Curve

Subject: Re: Photon Transfer Curve
From: pkuschak@xxxxxxxxxxx
Date: 11 Dec 2006 08:13:22 -0800
Newsgroups: sci.astro.ccd-imaging
Hi Jens,

Ok.  I think I'm on to something here ...

The read noise is high: about 280 e rms.  At saturation, the noise  is
750 e rms.  This is only about 2.7 times the read noise.  So, I surmise
I'm not actually ever reaching the shot-noise limited region!

What threw me was that I was able to fit (with low residual error) a
line to a major portion of the curve, which I assumed to be the
shot-noise limited region.  I no longer believe this is the case.

However, I still have high dynamic range: saturation = 500ke.  So
dynamic range is 20*log(500000/280) = 65dB.  Is it strange that I can
have both high dynamic range and high read noise?  I know the two are
somewhat decoupled, because the full well is quite high, but something
seems a little off here.

Best regards,
Patrick


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