Contrast ratio results for HP 2511x

Black
Contrast ratio	1167:1
Monitor model	HP 2511x
Submitted	14 Dec 2014 19:18 CET, by 108.7..
Camera model	Canon PowerShot SD1400 IS
Processing remarks	Warning: image file 3 is too bright to be a dark photo. Maybe you mixed up the files?
Screen photo	[open image]
Luminance	0.15 cd/m2
Luminance spread	0.02 cd/m2 (2 standard deviations)
Exposure value	–3.5 stops (aim for –2 to –3)
Exposure spread	0.22 stops
Area used for calculation	0.396 x 0.396
Camera settings	Exposure time: 1 ISO: 400 F-number: 2.8 Focal length: 27.4 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	173 cd/m2
Luminance spread	21 cd/m2 (2 standard deviations)
Exposure value	–2.28 stops (aim for –2 to –3)
Exposure spread	0.17 stops
Area used for calculation	0.396 x 0.396
Camera settings	Exposure time: 1/501 ISO: 400 F-number: 2.8 Focal length: 27.4 mm (35 mm equivalent) Exposure compensation: 0
Black at screen edge
Screen photo	[open image]
Luminance	173 cd/m2
Luminance spread	21 cd/m2 (2 standard deviations)
Exposure value	–2.28 stops (aim for –2 to –3)
Exposure spread	0.17 stops
Area used for calculation	0.396 x 0.396
Camera settings	Exposure time: 1/501 ISO: 400 F-number: 2.8 Focal length: 27.4 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.