Really effective ?

  • Hello,
    I can't remember where, but I read that software blue light reduction didn't work because the rays were still emitted even if screen looks yellow, and that the only way to prevent harmful effect of blue light was to use physical material like coated glasses or plastic filter.

    What's your opinion on this, and what research do you have to support that flux effectively reduce blue light perceived by the eye .


  • I can tell you from my experience that the only blue light I see goes up toward the ceiling and down toward my desk but not straight out toward my eyes. I can't see the bluish light unless I have a white sheet of paper on my desk right in front of my monitor (or some other white thing). The ceiling is too high for me to see the blue light that goes up. The light that goes down is too dim to affect me because I also lower my monitor's brightness, which is crucial in maximizing f.lux's effectiveness.

    I can also tell you that I can feel a big difference between 6500K and 1200K, even when I'm not tired. At the moment, I'm tired and getting ready for bed as I'm typing this actually. I use nothing but red light from one of these:

    I also have f.lux set to 1200K (800K actually, but I'm using a special Windows trick by making a change to the Registry), and my monitor's brightness is at 10%. Just to test this right now, I decided to disable f.lux and sure enough, as expected, I really felt a huge difference. Disabling f.lux brings it back to 6500K and even with my monitor dimmed very low, that blast of blue light was energizing. A better word is "alerting".

    So yeah, f.lux is very effective. As long as you are doing your best to avoid blue light in the rest of your home, f.lux is going to work "as advertised" because its job is to enable you to use your computer without being blasted by blue light.

  • @brakkar Reducing the blue (and a bit of green where possible) light emission, (straight out) from the monitor works extremely well. You are usually at least 18 or more inches away from a desktop monitor. After typing that I just inverted my colors.

    Anyway, with the more yellow light, further away, the very minimal blue light from the edges or sharp angles will not affect sleep in a currently easy (or worthwhile) to measure way. Basically, don't worry about it.

    What helps even more is inverting the colors. The only way I know how to do this is to open the magnifier in Windows 7 (It's a really great tool, and works perfectly!), and do Ctrl + Alt + I. Then this forum will have a black background with orange elements. F.lux helps a ton!

  • Darkroom Mode inverts the colors too.

  • @brakkar I am thinking you probably read that on a site selling physical filters! There is a lot of misinformation and confusion out there, I've seen some whoppers. A lot of the physical filters don't do anything - light that's alerting comes in a fairly wide range of bandwidths (so even filtering 100% of just 450nm wouldn't do all that much). Many of the "blue blockers" filter out less than 10% of only a narrow band of wavelengths.

    All that said, it's complicated, and some things that are very dim may have blue light but won't have much of an affect on your sleep. Remember that this is all still an ongoing topic of research.

    Have you checked out our project? It compares measurements of different light sources, physical filters, and f.lux settings using reference grade spectroradiometers (and incorporates some of our models of screen size and so on).

  • @lorna Thanks for your answer. It certainly was on a physical filter site that I read that.
    So for example, if I choose on fluxometer site macbook pro 2014 and flux setting of 4100k... the spectrogram I see is what you really measured with your spectroradiometer for that setting one real mbp ?

  • @brakkar Yes, they really did! The team LOVES measuring stuff, they even had measurements (not measured by them) of PAINT colors! They took it down though, but there were quite a few.

  • The paint samples were by someone else, but yeah we're a little nuts about this stuff.

  • Well,
    I removed my physical filter and used flux at 3700K (+ the reduced white point of my mbp screen that should have me at around 3K) and I must say it is indeed as, if not more efficient than my physical filter. I don't feel this burning sensation. When I put back 6500k I can't stare at the screen 1 minute without tears in my eyes.

    There are many advantages using flux:

    • Physical filter was a bit to small for my screen
    • Physical filter added huge glaring effect and got dirty more easily
    • I could not close my mbp properly
    • I can use any screen and i'll be able to have the flux effect, because there are no physical filter for all screen size, in particular that exotic square 27 inches Eizo that I contemplate buying :)

  • Omg, if you have tears in your eyes, does that mean you're sleep-deprived? The only time my eyes well up with tears at bright light is when I desperately need sleep.

  • @brakkar which physical filter were you using if you don't mind me asking? Some of them are quite effective, but they are deep orange.

  • Hi,
    I use one from Fiara. It's not deep orange, more lite yellow.

Log in to reply