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15:12 | anuejn | vup: polyrhythm se6astian isnt there like pretty accurate spectral response in the datasheet of the image sensor?
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15:12 | anuejn | cant we just trust this data?
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15:12 | anuejn | at least for relative values?
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15:14 | vup | se6astian: can do later
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15:15 | vup | anuejn: maybe, it doesn't really specify errorbars
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15:15 | anuejn | could we 'just' derive all our color science from that
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15:16 | anuejn | or and why is that a naive thought
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15:16 | vup | So my assumption is they measured exactly one sensor
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15:16 | anuejn | vup: so no errors ;)
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15:16 | anuejn | quite plausible
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15:17 | se6astian | no idea tbh
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15:17 | se6astian | I wouldnt even know how to translate the response curve to a color interpretation
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15:18 | vup | Also it doesnt say anything about the response curve wrt intensity
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15:20 | anuejn | wrt intensity?
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15:21 | anuejn | but theoretically there is all the data to generate the two color matrices from this diagram if we assume that the sensor is perfectly linear?
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18:06 | vup | Probably, although it could also be impossible
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18:06 | vup | (In general, regardless of the data we have)
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19:00 | anuejn | why or why not?
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19:18 | Bertl | it's impossible because it won't work with a matrix ;)
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19:19 | anuejn | what wont work with a matrix?
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19:19 | anuejn | like, you have to specify two matrices for the dng to be developed correctly
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19:19 | anuejn | for two different iluminants
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19:20 | anuejn | to map sensor output into CIEXYZ
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19:20 | Bertl | we already know, we need something more powerful than a matrix (or two)
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19:23 | anuejn | for nonlinear response of the image sensor?
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19:25 | anuejn | but even if we wanted to create something like a 3d lut, couldnt we just "simulate" test pics using the spectral response, the spectrum of some standart iluminant and the absorbing spectrum of our color targets?
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19:30 | Bertl | yes, in theory we could, we also need to take the lens into account though
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19:31 | Bertl | I was just commenting on the matrix part, hence the ';)'
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20:20 | anuejn | okay
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20:49 | anuejn | huh turns out you can have 3d luts in dng files
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20:49 | anuejn | but in a kind of odd form
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20:50 | anuejn | only in hsv form
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21:21 | anuejn | se6astian: do you have a link to the filter spectral response data for me?
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21:22 | se6astian | The uv it filters?
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21:23 | se6astian | *IR
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22:00 | anuejn | yup
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23:44 | anuejn | I obtained a pair of plausible color matrices from the datasheet spectral response :)
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23:46 | anuejn | (see https://github.com/anuejn/cmv12k_color_response/blob/main/color_matrices.ipynb)
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23:50 | anuejn | and it even kind of works in davinci resolve
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