Contrast ratio results

Contrast ratio 2423:1
Monitor model
Submitted 02 Dec 2020 04:24 CET, by 108.18.*.*
Camera model Canon EOS Rebel T7i
Processing remarks

image file 1: Warning: image includes screen edges or something that's not a monitor. Hold the camera close to the screen.
Warning: image file 1: Underexposed. Please increase the shutter time.
Note: image file 1: suggested exposure time: 15.9 s (Set EV to +8.5)
image file 2: Warning: image includes screen edges or something that's not a monitor. Hold the camera close to the screen.
Note: image file 2: suggested exposure time: 1/150 s (Set EV to -1.2)

Black
Screen photo
Luminance 0.05 cd/m2
Luminance spread 0.04 cd/m2 (2 standard deviations)
Exposure value –10.95 stops   (aim for –2 to –3)
Exposure spread 1.04 stops
Area used for calculation 0.371 x 0.496
Camera settings Exposure time: 1/22   ISO: 400   F-number: 4.8
Focal length: 28 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
Luminance 132 cd/m2
Luminance spread 64 cd/m2 (2 standard deviations)
Exposure value –1.25 stops   (aim for –2 to –3)
Exposure spread 0.71 stops
Area used for calculation 0.371 x 0.496
Camera settings Exposure time: 1/64   ISO: 400   F-number: 4.8
Focal length: 28 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.