ejmartin wrote: alundeb wrote:
Estimate of the photon full well (saturation) of the 7D
The background of the still life scene used by image-resource.com has some areas that are uniformly lit, and clean.
For high ISO\'s (6400-12800), the photon shot noise is practically all that contributes to the Standard Deviation (or variance, or Sigma) in those areas.
Sorry, it is at low ISO\'s that photon shot noise is all that contributes in bright areas. At high ISO there is substantial contribution from the std dev of pixel RAW values from the read noise, at any illumination level. In the top stop or two at base ISO there can be a potential contribution from pixel response nonuniformity, so either choose a midtone at base ISO or a bright area at ISO 200.
I get that in principle, but for this camera, the read noise at high ISO is extremely low ( see one of my later posts above).
In this case, the Std.dev at ISO 12800 is 288 and the read noise is 22.
The Std.dev at ISO 200 is 36 and the read noise is 4.7
Sep 03, 2009 at 02:19 AM
Previous versions of alundeb's message #7488548 « 7D noise vs 50D numbers »
