Flux different levels of distortion
When running flux at 1900K on my different devices an old Vaio laptop running windows 7 versus a Macbook pro w/ touchbar running High Sierra, I see a large difference in color distortion between the two devices the Macbook looks almost completely red but the Vaio seems to maintain a greater proportion of its color integrity. Why is this the case? Does setting the color temperature to the same value block a similar amount of blue light? Thank you in advance for your answers.
(I posted this reply to your other thread as well)
This is determined by the color accuracy of the display. F.lux can only do so much. The rest is up to the color accuracy of the display.
Generally, 1900K should be more than good enough for just about any display because that's an extremely warm setting. It's not blocking blue light. It's reducing how much is being sent to the display by simply changing the color temperature. However, again, the display's color accuracy will determine the actual appearance of the color temperature that you have selected, such as 1900K or 6500K, etc. Most displays aren't accurate. F.lux is at the mercy of whatever the display can do. So, it really doesn't matter what color temperature number you select, just as long as it's giving you the physical results in your body that you want. It's kind of like paying too much attention to the volume number when adjusting audio volume, or like paying too much attention to a house thermostat's temperature setting and allowing that number to determine your perception of the actual results.
So really, don't worry about it. Y'know? Don't place too much importance on the color temperature number that you have selected in f.lux. It's more for your reference so that you can know which settings work best for you with your display and your body. You'll never get any display to accurately or perfectly produce precisely 1900K (or whatever number you select), but that's not the point nor is it the goal. The point of f.lux and the goal is to avoid alerting/stimulating light when you're trying to unwind at the end of your day so that you aren't having your melatonin production interrupted or delayed. There's no specific setting that works precisely the same for everyone. You just have to find what works for you, but generally, 1900K is an extremely good starting point no matter how bad the display might be.
So, there's no right or wrong setting or anything like that. Just use what feels right. You'll know when it's right because you'll feel it. If you're in doubt, switch back to 6500K for a few seconds and see how you feel. Compare that feeling to how you felt when you had 1900K selected. I can almost guarantee you that even with a crappy monitor that emits too much blue light, 1900K should be more than enough to feel good and to enable proper preparation for sleep.
Of course, this is all assuming that you're not being exposed to alerting/stimulating light from other sources, such as your indoor lighting or the TV or other devices that can't use f.lux. F.lux is simply a way to enable you to use your computer at bedtime without being blasted by alerting light, assuming you've already done a proper job of avoiding alerting light from everywhere else in your home.
So yeah, it's not a problem that you have two different results from two different displays even though the same color temperature is selected in f.lux, just as long as the f.lux setting you've selected is causing the display to produce light that's not too alerting for you. To that end, make sure you also reduce the display's brightness a lot using the computer's brightness controls. I know that f.lux has a brightness control, but that's only to be used as a supplement to your display's actual brightness adjustments if needed because f.lux's brightness control only adjusts the black level. Your computer's display brightness control should adjust the brightness of the display's backlight.