Hello,I'm experimenting with shooting RAWs of a known light-source and predicting the resulting RAW pixel values. In theory, there is the traditional photographic exposure system where ISO, Aperture, and shutter speed are interrelated. At ISO 100, Tv (shutter time)=1s and Av (aperture) of f/1, you get 0 EV. You can then exchange units called "stops" in each of the settings to balance or change the EV. A change of 1 stop in Av is in a ratio of sqrt(2), so 4, 5.6, and 8 would be 3 stops (note, it should be 5.7 but the values are rounded in some arbitrary way).
For example, from f/4 to f/8 should be exactly 4, but it's only 2.7. Does anyone know where I'm going wrong in my calculations?
Very helpful, thanks!My camera is sx50hs fw:100b with propset 5.I used the debug display on page 3 and the location 23 didn't change as I changed Av in manual mode.
if av96_end <= av96_start then
Your methods are working. I'll have to try my way as well. The sensor is so hot, that black level is significantly affected though. How does this log compare to your experiments?
I assume your script subtracts black level
The predicted ratio is 2^(1/(2*96/32)), so 96/32 means 1/3 stop, and 2 is the ratio of 1 stop, so this is 2^1/6.
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