Hi James, On Sun, 10 Sep 2006 12:56:52 +1000, J and K Messervy wrote:
>Umm, not being an electrical engineer, physicist or mathematician, it's all >greek to me. Well I am (an electrical engineer :-) and there ARE some interesting figures in there: - Saturation signal: 40K electrons Meaning THIS particular sensor will saturate a well (one pixel) when it has a charge of about 40000 electrons. This would be the maximum WHITE level to be recorded. - Quantum efficiency, about 0.33 Meaning you need an average of 3 photons (light :-) to get a single electron added to the charge of the pixel. (meaning about 120000 photons to reach saturation) - Total sensor noise: 17 electrons Meaning the noise from the sensor alone is 1 / 2350 of the saturation level, which is just over 11 stops in range ... This is the major factor in setting the minimum recordable light levels (BLACK), but I am unsure how close you could put it to get reasonable noise levels. You probably need to be several stops ABOVE this point to have acceptable shadow detail left ... And the rest of the electronics will add some noise too. Of course this is just ONE sensor, from KODAK, and the values may not be representative for the ones in Pentax cameras :-) But it IS nearly the same technology ... Regards, JvW ------------------------------------------------------------------ Jan van Wijk; http://www.dfsee.com/gallery -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
