Contrast ratio results

Black
Contrast ratio	13:1
Monitor model
Submitted	30 Dec 2017 06:25 CET, by 71.87..
Camera model	Canon EOS 70D
Processing remarks	Warning: image file 1: camera was zoomed in too much. 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 2: camera was zoomed in too much. image file 2: Warning: image includes screen edges or something that's not a monitor. Hold the camera close to the screen. Warning: image file 3: camera was zoomed in too much. image file 3: Warning: image includes screen edges or something that's not a monitor. Hold the camera close to the screen. Warning: Image ISO settings are not the same. Warning: Image focal lengths/zoom levels are not the same. Warning: image file 3 is too bright to be a dark photo. Maybe you mixed up the files?
Screen photo	[open image]
Luminance	31 cd/m2
Luminance spread	87 cd/m2 (2 standard deviations)
Exposure value	–3.13 stops (aim for –2 to –3)
Exposure spread	4.25 stops
Area used for calculation	1 x 1
Camera settings	Exposure time: 1/80 ISO: 800 F-number: 5.6 Focal length: 131 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	412 cd/m2
Luminance spread	546 cd/m2 (2 standard deviations)
Exposure value	–1.7 stops (aim for –2 to –3)
Exposure spread	2.3 stops
Area used for calculation	1 x 0.506
Camera settings	Exposure time: 1/125 ISO: 250 F-number: 5.6 Focal length: 142 mm (35 mm equivalent) Exposure compensation: 0
Black at screen edge
Screen photo	[open image]
Luminance	750 cd/m2
Luminance spread	1278 cd/m2 (2 standard deviations)
Exposure value	–1.48 stops (aim for –2 to –3)
Exposure spread	3.65 stops
Area used for calculation	1 x 1
Camera settings	Exposure time: 1/125 ISO: 160 F-number: 5.6 Focal length: 147 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.