Colourmanagement - does flux drop the LUT

  • Hi

    This is specifically a Mac question.

    I'm a colormanagement guy and I am also interested in health, so not preserving natural circadian rhythms is something I approve of. That means I think flux is a great idea for those working into the evening on email, text etc. as it reduces damaging blue light exposure.
    But, plainly, its not great for editing photographs with consistency whilst it's active because consistency is king in that arena. So both the screen and room illumination should ideally stay consistent. (That means the evening isn't a great time to be photo editing if you value your sleep because your calibrated working environment is boing to disturb your circadian rhythms)

    I'd like to use flux myself, but wanted to be sure that it doesn't remove the calibration LUT (look up table) from the Mac's video card.
    As you know, when a screen is calibrated and profiled using a software utility and colorimeter an LUT is loaded to fulfil the calibration part of the process. Next, the calibrated screen is profiled and that icc profile helps apps like Photoshop to provide accurate on screen display of images etc.

    When the profile is swopped in Apples System Preferences / display/ color dialog, Apple load the newly selected profile's LUT - because the LUT and profile are inseparable if acuuracy is required.

    I'd like to know how flux works, does it drop the video LUT or replace it when flux becomes active at night? Then does flux put it back (totally unchanged)? Or, is flux perhaps always involved in the loading of the LUT and it's associated icc profile?
    Does flux achieve the change in screen appearance by adjusting the LUT - or replacing it?

    I need to know that my calibration (LUT) and profile is entirely unadjusted during daylight (working) hours and that flux only changes things after sunset kicks in. And, once daylight returns, does flux put things back just exactly as they were?
    Also, if I get a photo to edit after sunset or have to test calibration software - and, to allow that, I disable flux for an hour from the dropdown menu (or use one of the other disable options), does the monitor screen return fully to its accurate calibrated state whilst flux is disabled?

    If flux is not for me, how do I remove it and be sure that it's gone?

    Thanks lots
    I hope my question is clear


  • @colourguy
    hey, I should have also written thanks lots for developing flux, its a really great idea.

    I've searched the forum pretty thoroughly and I do see people n Macs having issues with uninstalling.
    I guess you are getting into the system to make the background stuff happen to screen appearance.
    It would be nice for potentail users to be able to test f.lux with the secur knowledge that should they not get on with it they have a reliable method to get rid of it completely.

    I hope your replies to the questions I asked above about the LUT etc. mean that I don't have to uninstall f.lux as I often work into the evening - but a post on how to properly uninstall all f.lux components would be a good addition to your FAQ.

    Again thanks
    I know your a small team. Great work.

  • Yes, we always read the system profile and load it, and we notice when it changes, and our adjustments consider it always.

    Regarding uninstall: f.lux is not hard to uninstall at all - you quit it and delete it. In the worst case (with one 'buggy' version of automatic brightness in the OS) a reboot is needed to clear the profile that the system picks up from us.

  • @herf

    Hi herf,

    thanks lots for that, good to know.