Contrast ratio results

Contrast ratio 12541:1
Monitor model
Submitted 12 Jun 2022 19:49 CEST, by 121.200.*.*
Camera model Apple iPhone XS Max
Processing remarks

Warning: image file 1: automatic white balance can cause inaccuracies.
image file 1: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time.
Warning: image file 1: Underexposed. Please increase the shutter time.
Note: image file 1: suggested exposure time: 1.1 s (Set EV to +4.2)
Warning: image file 2: automatic white balance can cause inaccuracies.
Note: image file 2: suggested exposure time: 1/230 s (Set EV to -1.6)
Warning: Image ISO settings are not the same.

Black
Screen photo
Luminance 0.04 cd/m2
Luminance spread 0.09 cd/m2 (2 standard deviations)
Exposure value –6.65 stops   (aim for –2 to –3)
Exposure spread 4.25 stops
Area used for calculation 0.345 x 0.46
Camera settings Exposure time: 1/16   ISO: 1250   F-number: 1.8
Focal length: 26 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
Luminance 443 cd/m2
Luminance spread 52 cd/m2 (2 standard deviations)
Exposure value –0.85 stops   (aim for –2 to –3)
Exposure spread 0.17 stops
Area used for calculation 0.345 x 0.46
Camera settings Exposure time: 1/72   ISO: 25   F-number: 1.8
Focal length: 26 mm   (35 mm equivalent)
Exposure compensation: 0

The luminance values in cd/m2 are not very reliable, since camera sensitivities can easily differ up to 50% from their nominal value. Typically, the real luminance is 30% lower than this number. The area used for calculation is chosen such that it corresponds to a viewing angle of ±14° horizontally and ±10.5° vertically, which is equivalent to viewing the screen from a distance of about 1.5 times the diagonal size.

Unfortunately, there is a lot of variation in how cameras use EXIF settings. If photos from your camera your produce unusable results, try coming back in a few days. I review submitted pictures regularly and try to fix problems.