Quote:
Originally Posted by Troy
Hi Ray,
Another technical but enjoyable post.
I'm not really sure how you measured the SNR mean signal / sd, but if I use the formula of
signal / noise (max histogram value / FireCapture noise estimate) would this work?
For example a histogram of 66 and noise estimate of 5 would give a SNR of 13.2
Also, would it be better to have the same exposure and gain settings and adjust the light source distance so they have the same histogram value?
Troy
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Thanks Guys.
Troy, Nebulosity shows the pixel stats for a 21x21 pixel region in an image - the mean signal/SD is the measure of SNR that I used.
Not sure what the Firecapture noise estimate is, but it should give a measure of the variance or SD in some form. The best signal estimate is probably the mean value rather than the maximum histogram value. The ratio of the mean to the noise estimate should give a signal to noise ratio that you could use for comparisons - might not be the same as I get, but would still be valid.
I tried to make the eval as simple as possible and the best test seemed to me to be to set the illumination at levels like those from a dim planet and then see what the cameras could do in both signal and signal/noise. Agree though that there are other equally valid ways to test.