4 ms·

Designer here. By maximising contrast, one is trading short-term legibility with long term legibility. The maximum amount of contrast is as problematic as almo

by gond 4y ago

Designer here. By maximising contrast, one is trading short-term legibility with long term legibility. The maximum amount of contrast is as problematic as almost no contrast. There is a maximum useable deviation to both ends. By approaching max contrast, it gets harder to read for longer periods, because your photoreceptors approaching exhaustion, creating an after image [1]. It may happen slow enough to go unnoticed for some periods but should be noticeable at the end of a day as eye strain. [1] https://en.m.wikipedia.org/wiki/Afterimage https://en.m.wikipedia.org/wiki/Afterimage

chrstphrknwtn 4y ago
For black text to be an issue, surely this is a sign that your screen is too bright?
- gond 4y ago
  Yes. The default settings on most monitors are unusable for reading. Calibrated reference screens for print reproduction are approaching 120-140 cd/m^2, which tends to be in the 20-35 percent rage of most monitor brightness settings (if the implemented brightness curve of the monitor scales lineary; not the case with some Eizo‘s. These use something akin to an inverted gamma 2.2 to compensate for the nonlinearity in brightness sensivity of humans) 120 cd then looks somewhat like matte paper. Ideally, this should shift up and down with the brightness of the environment the screen is put into. That is why most serious photometers/colorimeters include ambient light sensors and consider the results during calibration.
- exodust 4y ago
  It's "too bright" because 100% white is being used and covers most of the screen. When most displays blast intense white light in your face at normal settings, it's not a screen brightness issue, it's a content brightness issue. Solved with controls such as dark modes, reading modes and options for users to customise. Obviously a lot of users prefer the full contrast experience, but many don't. Providing user choice is best strategy.
mattkrause 4y ago
The neuroscience of after-images is a lot more complicated. It's certainly possible to cause them by "bleaching" photo-pigments, but this requires extremely bright light. Other mechanisms likely produce the after-effects you normally encounter, and even there, eye movements (large and small) should help counter-act them unless the stimulus is very large and bright. I have no doubt that overly contrast-y web pages can cause eye strain, but it's usually not because they're exhausting photoreceptors.
kentonv 4y ago
This sounds like pseudoscience to me. I regularly spend all day reading full-black-on-full-white and I don't experience this problem.
- spiderice 4y ago
  At the very least GP included a some sort of source (a link to an interesting wikipedia article). You dismissed the source with an anecdote. Not sure you're the one who should be making claims about pseudoscience.
  - marginalia_nu 4y ago
    GP's source doesn't actually motivate why an after-image is tiring for the eyes. I'd associate eyestrain with the muscles in the eye. Like you can give yourself eye-strain by quickly moving the focus from close to far-away a couple of times. Meanwhile, after-images are a neurological artifact. They do not cause your eyes to change focus, and are not caused by the muscles in the eye. Although extremely bright light may strain the eyes in the same way your eyes may be sore from contracting if you go outside on a bright summer day.
    - gond 4y ago
      Regarding the pseudoscience argument, maybe this helps a bit: as far as I understood it, there are two types of after image: One is a neurological artefact, the other one is a biochemical one. What I described earlier as exhaustion is buried in a process called visual cycle, which is a biochemical process. If enough photons of a given wavelength hitting special molecules of a part of your retina, these molecules run through a replenishing cycle after photon absorption to run through the same loop again and again. If light source is strong enough, the cycle is not adequate to account for the incoming mass of photons, essentially triggering temporary deactivation. The molecules responsible for colour vision register the inverse of the incoming wavelength, as in: the absence of all other wavelengths registered gets interpreted as the colour one sees. This essentially creates the yellow after image if one looks at an object with strong red and blue content. This is a can of worms and there is more involved, even on the side of the emitter which is why there is measurement in watts per steradian going on but my knowledge ends here. Maybe a Biologist can chime in. [1]https://en.m.wikipedia.org/wiki/Visual_cycle https://en.m.wikipedia.org/wiki/Visual_cycle
eirikbakke 4y ago
This completely depends on the reader's lighting conditions and time of day. If I'm sitting on my laptop in daylight, outdoors or in a room with large windows, I'd really like to max out the contrast while reading. Later in the day, the "Night Light" feature that's built into Windows 11 will reduce the contrast and increase the color temperature towards a yellower hue. (In past years I used f.lux for this.) This kind of adjustment is not something each website should try to do. It's a system-wide setting that needs to take into account e.g. local sunrise/sundown times, like Night Light does. (And on iPhones, there's a light sensor that takes care of this.)
- gond 4y ago
  Yes. I already mentioned this 5 posts down below as it did not fit here.
- lukego 4y ago
  Videographers would recommend using the full dynamic range that is available, right? That way you are providing maximum detail and letting other systems (e.g. screen, room light, human visual system) scale as appropriate. Even if your scene were in the middle of the night you would still use your brightest white ("FFFFFF") for the least-dark moonlit areas. (Striking recent example is The Northman fighting in the caves.) In that context I wonder if the motivation for recommending near-white and near-black, i.e. foregoing dynamic range for no intrinsic benefit, is for contrast against other things in the user's field of view e.g. large images, browser toolbars, popup notifications, etc.
  - kuschku 4y ago
    Videographers never use colors brighter than #EBEBEB or darker than #101010. That's the definition of "broadcast safe" or "video range" colors.
avereveard 4y ago
that depends on lighting conditions and guess what, it's far easier and more pleasant to use all contrast available in color and tone it down with the brightness setting of the monitor, than doing grays on grays and having to shade or crank up contrast in the monitor
- gond 4y ago
  Yes it does depend on lighting, see my other comment. No, ‘Maximum contrast everywhere’ given as a directive without consideration is not a solution and will increase the problem. Consider things beyond HDR displays: At technology progresses, we will approach superbright display technologies which will surpass the dynamic range of the human visual system. Technically, these will be as bright as light bulbs and brighter and could be used as such. Going by that max brightness directive, we will all stare happily into a direct light source one day. Or one is happily busy dragging the brightness slider up and down the whole day, one at a time for every app and site. It won’t work. To solve this, we would need tone mapping at the latest pipeline stage, everywhere. And this will, of course, again reduce contrast, but this time, by design. The other major problem is: by leaving it all to the users (all three dimensions of the now prevalent color model), one throws every standard out of the window. One website will send out 4000 nits, the next one 350. One display can handle it, the other cannot. Color shifts abundant. How should that be accounted for? Furthermore, your model makes it impossible to design for: this removes the visual target platform and puts legibility and qualitative design principles at the mercy of technological progress. So solve this with the tech available, there were several agreements made to specify calibration targets - which include brightness and contrast settings, aka gamma in more than one dimension. In a perfect world, no screen would leave the factory without a built-in calibration device and an ambient light sensor. One more problem, the constant intermixing of use cases while discussing HDR displays: not every use case needs an HDR treatment. It does not make any sense. The main problem HDR solves is that content creators are not forced to squeeze 10 pounds into an 6 pound bag anymore. And if your display supports this, you can benefit from the full color space the content creator wanted the observer to see. Which is totally nice for hundreds of use cases. However, staring at a pitch black font next to a white background which emits 20.000 cd/m^2 would be painful.

by gond 4y ago

chrstphrknwtn 4y ago

For black text to be an issue, surely this is a sign that your screen is too bright?

gond 4y ago
Yes. The default settings on most monitors are unusable for reading. Calibrated reference screens for print reproduction are approaching 120-140 cd/m^2, which tends to be in the 20-35 percent rage of most monitor brightness settings (if the implemented brightness curve of the monitor scales lineary; not the case with some Eizo‘s. These use something akin to an inverted gamma 2.2 to compensate for the nonlinearity in brightness sensivity of humans) 120 cd then looks somewhat like matte paper. Ideally, this should shift up and down with the brightness of the environment the screen is put into. That is why most serious photometers/colorimeters include ambient light sensors and consider the results during calibration.
exodust 4y ago
It's "too bright" because 100% white is being used and covers most of the screen. When most displays blast intense white light in your face at normal settings, it's not a screen brightness issue, it's a content brightness issue. Solved with controls such as dark modes, reading modes and options for users to customise. Obviously a lot of users prefer the full contrast experience, but many don't. Providing user choice is best strategy.

mattkrause 4y ago

The neuroscience of after-images is a lot more complicated. It's certainly possible to cause them by "bleaching" photo-pigments, but this requires extremely bright light. Other mechanisms likely produce the after-effects you normally encounter, and even there, eye movements (large and small) should help counter-act them unless the stimulus is very large and bright. I have no doubt that overly contrast-y web pages can cause eye strain, but it's usually not because they're exhausting photoreceptors.

kentonv 4y ago

This sounds like pseudoscience to me. I regularly spend all day reading full-black-on-full-white and I don't experience this problem.

spiderice 4y ago
At the very least GP included a some sort of source (a link to an interesting wikipedia article). You dismissed the source with an anecdote. Not sure you're the one who should be making claims about pseudoscience.
- marginalia_nu 4y ago
  GP's source doesn't actually motivate why an after-image is tiring for the eyes. I'd associate eyestrain with the muscles in the eye. Like you can give yourself eye-strain by quickly moving the focus from close to far-away a couple of times. Meanwhile, after-images are a neurological artifact. They do not cause your eyes to change focus, and are not caused by the muscles in the eye. Although extremely bright light may strain the eyes in the same way your eyes may be sore from contracting if you go outside on a bright summer day.
  - gond 4y ago
    Regarding the pseudoscience argument, maybe this helps a bit: as far as I understood it, there are two types of after image: One is a neurological artefact, the other one is a biochemical one. What I described earlier as exhaustion is buried in a process called visual cycle, which is a biochemical process. If enough photons of a given wavelength hitting special molecules of a part of your retina, these molecules run through a replenishing cycle after photon absorption to run through the same loop again and again. If light source is strong enough, the cycle is not adequate to account for the incoming mass of photons, essentially triggering temporary deactivation. The molecules responsible for colour vision register the inverse of the incoming wavelength, as in: the absence of all other wavelengths registered gets interpreted as the colour one sees. This essentially creates the yellow after image if one looks at an object with strong red and blue content. This is a can of worms and there is more involved, even on the side of the emitter which is why there is measurement in watts per steradian going on but my knowledge ends here. Maybe a Biologist can chime in. [1]https://en.m.wikipedia.org/wiki/Visual_cycle https://en.m.wikipedia.org/wiki/Visual_cycle

eirikbakke 4y ago

This completely depends on the reader's lighting conditions and time of day. If I'm sitting on my laptop in daylight, outdoors or in a room with large windows, I'd really like to max out the contrast while reading. Later in the day, the "Night Light" feature that's built into Windows 11 will reduce the contrast and increase the color temperature towards a yellower hue. (In past years I used f.lux for this.) This kind of adjustment is not something each website should try to do. It's a system-wide setting that needs to take into account e.g. local sunrise/sundown times, like Night Light does. (And on iPhones, there's a light sensor that takes care of this.)

gond 4y ago
Yes. I already mentioned this 5 posts down below as it did not fit here.
lukego 4y ago
Videographers would recommend using the full dynamic range that is available, right? That way you are providing maximum detail and letting other systems (e.g. screen, room light, human visual system) scale as appropriate. Even if your scene were in the middle of the night you would still use your brightest white ("FFFFFF") for the least-dark moonlit areas. (Striking recent example is The Northman fighting in the caves.) In that context I wonder if the motivation for recommending near-white and near-black, i.e. foregoing dynamic range for no intrinsic benefit, is for contrast against other things in the user's field of view e.g. large images, browser toolbars, popup notifications, etc.
- kuschku 4y ago
  Videographers never use colors brighter than #EBEBEB or darker than #101010. That's the definition of "broadcast safe" or "video range" colors.

avereveard 4y ago

that depends on lighting conditions and guess what, it's far easier and more pleasant to use all contrast available in color and tone it down with the brightness setting of the monitor, than doing grays on grays and having to shade or crank up contrast in the monitor

gond 4y ago
Yes it does depend on lighting, see my other comment. No, ‘Maximum contrast everywhere’ given as a directive without consideration is not a solution and will increase the problem. Consider things beyond HDR displays: At technology progresses, we will approach superbright display technologies which will surpass the dynamic range of the human visual system. Technically, these will be as bright as light bulbs and brighter and could be used as such. Going by that max brightness directive, we will all stare happily into a direct light source one day. Or one is happily busy dragging the brightness slider up and down the whole day, one at a time for every app and site. It won’t work. To solve this, we would need tone mapping at the latest pipeline stage, everywhere. And this will, of course, again reduce contrast, but this time, by design. The other major problem is: by leaving it all to the users (all three dimensions of the now prevalent color model), one throws every standard out of the window. One website will send out 4000 nits, the next one 350. One display can handle it, the other cannot. Color shifts abundant. How should that be accounted for? Furthermore, your model makes it impossible to design for: this removes the visual target platform and puts legibility and qualitative design principles at the mercy of technological progress. So solve this with the tech available, there were several agreements made to specify calibration targets - which include brightness and contrast settings, aka gamma in more than one dimension. In a perfect world, no screen would leave the factory without a built-in calibration device and an ambient light sensor. One more problem, the constant intermixing of use cases while discussing HDR displays: not every use case needs an HDR treatment. It does not make any sense. The main problem HDR solves is that content creators are not forced to squeeze 10 pounds into an 6 pound bag anymore. And if your display supports this, you can benefit from the full color space the content creator wanted the observer to see. Which is totally nice for hundreds of use cases. However, staring at a pitch black font next to a white background which emits 20.000 cd/m^2 would be painful.