Contrast ratio results

Contrast ratio 2104:1
Monitor model
Submitted 21 Dec 2020 08:42 CET, by 70.172.*.*
Camera model Apple iPhone XR
Processing remarks

Warning: image file 1: camera was zoomed in too much.
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: 5.0 s (Set EV to +5.7)
Warning: image file 2: automatic white balance can cause inaccuracies.
Warning: image file 2: Overexposed. Please decrease the shutter time.
Note: image file 2: suggested exposure time: 1/170 s (Set EV to +1.5)
Warning: Image ISO settings are not the same.

Black
Screen photo
Luminance 0.01 cd/m2
Luminance spread 0.01 cd/m2 (2 standard deviations)
Exposure value –6.81 stops   (aim for –2 to –3)
Exposure spread 1.31 stops
Area used for calculation 1 x 1
Camera settings Exposure time: 1/4   ISO: 1600   F-number: 1.8
Focal length: 130 mm   (35 mm equivalent)
Exposure compensation: 1.37
White
Screen photo
Luminance 13 cd/m2
Luminance spread 0 cd/m2 (2 standard deviations)
Exposure value –0 stops   (aim for –2 to –3)
Exposure spread 0 stops
Area used for calculation 0.345 x 0.46
Camera settings Exposure time: 1/30   ISO: 640   F-number: 1.8
Focal length: 26 mm   (35 mm equivalent)
Exposure compensation: 4

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.