A 3W LED light should be about as bright as a 40W incandescent light bulb. The illusion of the brightness can vary depending on the color. Blue will seem the brightest and red will seem the dimmest. Of course, the wattage efficiency of the LED light comes into play as well. Less efficiency results in less light output.
@herf Thanks, that really helps. So, bright light will still have it's normal effect, along with this "extra effect" after dim light, so you still say dim light before that, will be better if the times aren't predictable. I'm glad I won't think too much into this effect now, but I'm glad it's on your research page.
I'm good on the dim bathroom light, I have two I can choose from, and one gets extremely hand burning hot (I have to turn it into the socket each time) using 20 watts, and the other no where near that level of heat using 24.5 watts. I like the dimmer more orange looking light, but wow it hurts! It's more orange, the other is a gold yellow and I don't like it as much.
@OpticalDesigner many tens of
thousands of f.lux users have written in already - instead of allowing it, they released Night Shift, which is really not effective enough - it's not as strong an intervention and it only works on new machines with bigger and brighter screens. Oops.
We would love it if people keep writing in and saying they'd like to see Apple allow real f.lux for iOS. Thank you!
@Bomag It's a good question and I don't have a certain answer for you. It may help just by reducing the peak brightness of the flickering, or it might be something about eliminating flickering in specific wavelengths. Just guessing. There is a a lot we don't know!
I have just about the same amount of love for f.lux and for Mike and Lorna (the developers), but for different reasons. I don't have any problems with my eyes or anything like that (not yet, at least), but I still feel that I absolutely do not want to live without f.lux!
@WarmScreenMan25 Thank you for sharing your experience, but what works for you is not for every person. It is extremely dependent on a number of variables, and personal preference is one of many. This forum is not the place to dispense this level of advice. Locking thread.
For anyone who would like to know more about the current science about biological effects of computer screens (you can experiment with age, distance, color and brightness) please visit https://fluxometer.com/rainbow.
This is pretty uninformed, both about science and about f.lux.
If you want to talk about sleep and alertness, you don't talk about 443nm light, you talk about the "blue-green" peak response of melanopsin (~488nm, and a wide range around it). They are really far off here.
f.lux has offered "soft" dimming (which helps with PWM) for 4 years now.
They claim to reduce color temperature to 4500K which removes <25% of the effects of bright light. Of course you can use f.lux to do this too - you can choose any setting you like.
It seems like they test displays for PWM, so that is nice because you may not want to buy a display that has it.
But once you do, it's pretty hard to avoid: many models will make PWM when not dimmed at all, or the power settings will dim the display slightly, all the time, or Intel's drivers will dim the screen automatically when you use a profile like the ones they suggest. And as I said, f.lux's dimming will be equivalent in any case.
Agree totally! I just could not believe there was no setting for bedtime.
I just turned 70. I get up at 07:30 and usually go to bed close to 23:30. I have no problems going to sleep, but do agree that late night screen time probably influences how long it takes me to fall asleep.
I have a friend who is even older than I am and has never slept more than 4 hours a night (difficult to keep up with him intellectually! he has so much more time than I to read and think). He would be totally dissatisfied with f.lux.
So, when are we getting a setting for how many hours we are normally active and awake, or bedtime or something similar.
There is a setting for sleeping in on the weekend, which I never do. Anyway: sleeping in on weekends is equivalent to providing yourself with one or more hours of jetlag.
@suosuo Turn down your monitor brightness well below 50%. Wave your hand in front of the screen. If you see a chop in the movement, then it is indeed PWM, modulating the speed at which the backlight "pulses" pure on, to pure off, with minimal fade in the backlight. The absence of a fading, is what causes a chop, that direct, near instant darkness in the screen, then right back to 100% brightness--this pulsing gives the illusion that it's not at full brightness but it still is. Be sure to look for "Flicker Free" monitors!
I think this is a key question because avoiding all light during the day can make sleep problems worse, and in some cases this might make headaches the next day worse as well (because you didn't sleep well or because your circadian system is not expecting bright light at certain times).
Overall I would say two things:
If you have really bad headaches "right now", I would do what you need to. Avoiding bright light is a great approach, and trying to increase light levels later in the day is sometimes possible too.
On most other days, most people should try to see enough bright "blue" light during the day (e.g., an hour outdoors) and keep things dimmer at night. This will let you sleep a little better at night, and if you do, maybe it will help headaches too.