Why do games have video calibration screens like this?

[SeeNoWeevil]

Why suggest just-above-black should be invisible? The majority of screens will suggest a particular portion is 'barely visible', which makes sense - but I've seen a few now like this. Using Full video levels you'd never want just above black to be invisible. The only explanation I can think of is they're encoded with black-than-black using Video levels, and then converted wrongly to Full. Or am I missing something?

 

[PixResearch]

Educated guess...

It may well be a hang over from legacy TV screens (eg: console compatability). Lots of TVs use YUV and the luma/brightness/Y channel doesn't go down to 0. At 8 bits per channel you should be able to show a brightness range (0->255), but TVs can only show (16-235). My guess would be that the image they want to be invisible is @ brightness 15.

Therefore you can't see the dark object when viewed on a TV (it snaps to "totally black") but when played back on a monitor you can see it. By setting your monitor to hide the object that wouldn't have been visible on a TV you can get the same experience/dynamic range regardless of the ability of your screen.

 

[SeeNoWeevil]

the image they want to be invisible is @ brightness 15.

That was my assumption too - but if your system is set to PC levels, 15 would be clipped off and invisible. If the lighter portion is 17, why tell the user to make it invisible?? On a correctly calibrated screen, the lighter portion should be just visible imo.

 

[tongue_of_colicab]

It's just a basic brightness check to account for room brightness.

Doing the calibration in a dark room is going to result in the game being unplayable in normal daylight conditions because the brightness would be way too low.

 

[kolsto]

Well, I guess that's because during the day there a different amount of light in your room that has an impact on a screen brightness.