Re: using digital camera

I think this is evidenced in scanning using CCD's, too. As nearly as I
can tell, CMOS somehow avoids this problem.

Pam

echiniscus@gmx.de wrote:
>
> > Why do you suppose that is?
> >
> > Pam
> >
> > Michael Keller wrote:
> > >...With digital, long exposures can lead to increased
> > > noise in the shadows.
>
> The CCD chips tend to give a signal not only when they are exposed to light
> but also to temperature. This leads to ´thermal noise´, that can be seen best
> in the dark parts of the image and that accumulates over time.
>
> Astronomers, who have kind of an addiction to long time exposures of dark
> skies, cool down their CCD cameras to minimize that noise.
>
> servus
>
> martin adler

-- 
Pamela G. Niedermayer
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