3 ms·
The Contrast Rebellion
- PaulHoule 6y agoI dunno. One topic of conversation in the house is how the dynamic range of prints (say Inkjet) interacts with the viewing conditions. For instance if is relatively dark and you are far away from the print it makes sense to lighten the dark areas so you can see more in them. Under good viewing conditions though the original looks better. It is like gamma correction but it applies to prints and not just screens. That article is missing the important thing which is knowing how to pick contrasting shades algorithmically, even if you never look at them. The accessibility guidelines for contrast are half of the knowledge, the other is knowing that contrast ratios are defined in terms of the L in the Lab color scheme.
- Myndex 6y agoThe "gamma" if you will for printed materials is usually defined as the "dot gain", for reflected light one of the key factors is the light adaptation of the eye at viewing. The WCAG 2 contrast guidelines are defined using relative luminance "Y", as in CIE XYZ, and not absolute luminance "L", even though they use the letter L somewhat incorrectly (not to mention incorrect math, but that's another story for another day). The 1.4.3 guidelines are not LAB which is more properly L*a*b*, as L* is perceptual lightness, not luminance. Interestingly though, the NEW method for WCAG 3 is APCA, which is using power curves very similar to L* perceptual lightness, but nevertheless is not a ratio. APCA is perceptually uniform, the old method is not, leading to a great deal of misunderstanding, and likely a motivating factor behind "Contrast Rebellion"...
- deleted 6y ago[deleted]
- PaulHoule 6y agothanks 4 the correction!
- FrozenVoid 6y agoI can't take any usability websites seriously when they waste 50% of screen width on empty margins.
- smoyer 6y agoFunny ... I just assume that's where the ads my blocker eliminated used to be.