Self modification of own scanner is very difficult, it is better to
buy another good one. But the noise of cheap scanner increases very
fast with time of use, it is very obvious with my UMAX 1220 (for
slides). I think it is very possible for a chip like CCD to have 20C
temp rise or even more after half an hour of operation, the
environment temp inside the flatbed will be raised by the fluorescence
tube and other power circuits too.
If my calculation is right a 4 times improvement is equal to a D-range
of around 0.6, it is a huge improvement.
C.H.Ling
HI100@xxxxxxx wrote:
>
> conductive losses on the front. Unless the CCD device is running very hot
> (seems unlikely since the dissipation is not huge usually) you don't even
> gain much with a 20C increment. Typically the dark current halves
> approximately every 10C reduction so 20C is a 1/4 of the noise current. Not a
> huge improvement especially as the circuit may be limited by the A/D
> convertor resolution or other factors not the detector.
>
> Regards,
> Tim Hughes
> >>Hi100@xxxxxxx<<
>
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