D800 bad for your computer.

Started Mar 23, 2012 | Discussions thread
DSPographer
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Re: My fit at ISO 100 is different
In reply to ejmartin, Mar 23, 2012

There is something wrong with Bob's curve fit at ISO 100. Here are my fit values:

  • Sensor Paramaters Derived From DXOmark.com Data *

ISO: Manufacturers ISO rating
m: Pixel saturation count in electrons
n: Pixel read noise in electrons
g%: Standard deviation of gain error (PRNU) in percent

res: Worst case difference between fitted SNR curve in dB and SNR data points in dB

NikonD800
ISO: 100 200 400 800 1600 3200 6400 12800 25600
m = 48818 24668 13350 6631 3549 1788 847 510 255
n = 4.55 3.56 3.37 2.86 2.86 2.95 2.60 3.28 3.70
g% = 0.52 0.55 0.54 0.53 0.68 0.84 0.21 1.42 2.42
res= 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Note that the fit residues are zero since DXOmarks SNR plots are parameterized the same way as my fit. I have noticed that the DXO values when the full well count is less than 1000 e- become noisy. So looking at the values for ISO 100 to 3200, the values don't seem to bounce around too badly.

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