Contrast ratio results for Dell p2417h

Contrast ratio 24607:1
Monitor model Dell p2417h
Submitted 20 Jul 2018 22:39 CEST, by 77.120.*.*
Camera model Canon EOS 40D
Processing remarks

Warning: image file 1: camera was zoomed in too much.
Warning: image file 1: Underexposed. Please increase the shutter time.
Note: image file 1: suggested exposure time: 45.3 s (Set EV to +5.8)
Warning: image file 2: camera was zoomed in too much.

Black
Screen photo
Luminance 0 cd/m2
Luminance spread 0 cd/m2 (2 standard deviations)
Exposure value –8.32 stops   (aim for –2 to –3)
Exposure spread 0.76 stops
Area used for calculation 1 x 1
Camera settings Exposure time: 0.8   ISO: 400   F-number: 1.4
Focal length: 81 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
Luminance 40 cd/m2
Luminance spread 12 cd/m2 (2 standard deviations)
Exposure value –1.04 stops   (aim for –2 to –3)
Exposure spread 0.45 stops
Area used for calculation 1 x 1
Camera settings Exposure time: 1/197   ISO: 400   F-number: 1.4
Focal length: 81 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.