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Hi Patrick,
> Ok. I think I'm on to something here ...
>
> The read noise is high: about 280 e rms.
Oh, this explains something.
Sensors normally has to be read out by CDS or dual slope integration
(weighted dsi is the best), and some sensors can be read without
destruction of the charges, so noise can be lowered by multiple
readouts.
Then there are sensors with charge multiplying processes, but this
increases the shot noise.
Timing and correct filtering are important for a low noise readout.
> 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.
Far off, if you ask me. High dynamic range doesnt increase the readout
noise in this amount. Sensors with such a high fullwell have sometimes
two different readout modes, one with a higher v/charge output and
decreased fullwell - but a slightly lower read-noise, and one with
the maximum fullwell and somewhat higher readout-noise.
But the values for good CCDs are somewhere about 5 and 8e_rms,
dependend on the speed and method of readout, higher than 20e should be
avoided.
I think you should use a acquisition board, designed or handmade for
the sensor.
Best regards,
Jens
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