Contrast ratio results

Black
Contrast ratio	56489:1
Monitor model
Submitted	11 Mar 2018 10:37 CET, by 108.80..
Camera model	Canon EOS 80D
Processing remarks	Warning: image file 1: automatic white balance can cause inaccuracies. Warning: image file 1: Underexposed. Please increase the shutter time. Note: image file 1: suggested exposure time: 341.8 s (Set EV to +13.8) 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 -2.0) Warning: image file 3: automatic white balance can cause inaccuracies. image file 3: Warning: image includes screen edges or something that's not a monitor. Hold the camera close to the screen. Warning: image file 3 is too bright to be a dark photo. Maybe you mixed up the files?
Screen photo	[open image]
Luminance	0 cd/m2
Luminance spread	0 cd/m2 (2 standard deviations)
Exposure value	–16.27 stops (aim for –2 to –3)
Exposure spread	2.1 stops
Area used for calculation	0.389 x 0.437
Camera settings	Exposure time: 1/41 ISO: 400 F-number: 3.5 Focal length: 28 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	77 cd/m2
Luminance spread	6 cd/m2 (2 standard deviations)
Exposure value	–0.49 stops (aim for –2 to –3)
Exposure spread	0.12 stops
Area used for calculation	0.389 x 0.437
Camera settings	Exposure time: 1/41 ISO: 400 F-number: 3.5 Focal length: 28 mm (35 mm equivalent) Exposure compensation: 0
Black at screen edge
Screen photo	[open image]
Luminance	35 cd/m2
Luminance spread	73 cd/m2 (2 standard deviations)
Exposure value	–1.6 stops (aim for –2 to –3)
Exposure spread	4.25 stops
Area used for calculation	0.389 x 0.437
Camera settings	Exposure time: 1/41 ISO: 400 F-number: 3.5 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.