Gray Screen - full screen
Uniformity check Β· white balance reference
- Reveal brightness uniformity problems (mura)
- White balance reference surface
- Comfortable mid-brightness background
- Exposure reference for cameras
Uniformity check Β· white balance reference
A mid-grey field exposes problems that neither white nor black will show. Panel uniformity issues β patches that read brighter or darker than their surroundings, known as mura β become visible against flat grey. In photography, middle grey is the reference point for exposure and white balance, so a grey screen can stand in for a grey card when nothing else is to hand.
Using a display as a light source is the standard workaround when there is no ring light to hand. A laptop or monitor already sits directly in front of you, so the angle is natural, and the large emitting area gives soft shadows. Full brightness usually blows out skin detail, so drop it to 30-60 per cent and use the colour temperature slider to set the tone. Turn on keep screen awake so the display does not sleep part way through.
For testing, leave brightness at 100 per cent and colour temperature neutral β otherwise you are inspecting an adjusted colour rather than the panel itself. Turn off night mode and blue light filters too. To check thoroughly, cycle through red, green, blue, white and black; the dead pixel test page does that automatically.
The export here builds the image in your browser rather than downloading a pre-made file from a server. A canvas is filled with the current colour and saved, which means any resolution works and whatever brightness and colour temperature you set is baked into the file.