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  • #10320
    JohnMLJ
    Participant

    Hi everyone,
    I am Giovanni Fragassi a Lighting designer, I found the project very interesting, congratulations!! Seeing what it is’ currently able to do I was wondering if it was also possible to view the TLCI values ​​in the application, TM-30; Out, R9 of the analyzed light, it would be super fantastic if there was that possibility.
    Good job everyone.

    Giovanni

    #10325
    theremino
    Keymaster

    I'm sorry but (as already explained several times) the only precise measurements that can be obtained from a WebCam are those of frequency (nanometers) and not intensity (milliwatt, lux or similar).

    The precision on the nanometers is given by geometric factors (number of lines in the lattice, angles and distances) and on these things he is not mistaken.

    Instead the intensity measurements should be based on the sensor response which is absolutely non-linear, and are even more damaged by the WebCam driver that "tries" to show an image as the human eye sees it. The driver and the WebCam don't care about Milliwatts, Lux, Out, R9 etc .., they only make sure that you see the image well even if the lighting conditions change. And in doing this they modify the intensities to their liking.

    Furthermore, the response of the WebCam sensors to the various wavelengths is far from constant. For a WebCam and its driver, the only thing that matters is that the final image is beautiful, after having passed it through only three numerical values ​​that correspond to R., G e B.

    #10327
    JohnMLJ
    Participant

    Thanks for the reply, obviously I didn't have too many illusions but I tried.

    Obviously the reasoning does not make a turn.
    So I assume that it is not possible to build such an instrument “home made”….

    Unfortunately, these devices are very expensive and I was hoping that open source could help.
    Thanks again for the detailed answer.

    Giovanni

    #10329
    theremino
    Keymaster

    For many uses, knowing the nanometers accurately is important and the accuracy we can achieve is very good.
    For intensities you will need to use other methods.

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