Contrast ratio results

Contrast ratio 393:1
Monitor model
Submitted 11 Aug 2022 21:56 CEST, by 82.79.*.*
Camera model Nokia Lumia 520
Processing remarks

Warning: image file 1: could not determine angle of view; assuming 38 mm lens (35 mm equivalent).
Warning: image file 1: Underexposed. Please increase the shutter time.
Note: image file 1: suggested exposure time: 1.9 s (Set EV to +3.9)
Warning: image file 2: could not determine angle of view; assuming 38 mm lens (35 mm equivalent).
Warning: image file 2: Overexposed. Please decrease the shutter time.
Note: image file 2: suggested exposure time: 1/200 s (Set EV to -2.0)

Black
Screen photo
Luminance 0.11 cd/m2
Luminance spread 0.07 cd/m2 (2 standard deviations)
Exposure value –6.45 stops   (aim for –2 to –3)
Exposure spread 0.99 stops
Area used for calculation 0.528 x 0.705
Camera settings Exposure time: 1/8   ISO: 400   F-number: 2.4
Focal length: 0 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
Luminance 44 cd/m2
Luminance spread 24 cd/m2 (2 standard deviations)
Exposure value –0.47 stops   (aim for –2 to –3)
Exposure spread 0.8 stops
Area used for calculation 0.528 x 0.705
Camera settings Exposure time: 1/50   ISO: 400   F-number: 2.4
Focal length: 0 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.