Contrast ratio results

Black
Contrast ratio	36:1
Monitor model
Submitted	10 Dec 2013 14:49 CET, by 140.118..
Camera model	Canon PowerShot G11
Processing remarks	Warning: image file 1: automatic white balance can cause inaccuracies. Warning: image file 2: automatic white balance can cause inaccuracies. image file 2: 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.
Screen photo	[open image]
Luminance	0.52 cd/m2
Luminance spread	0.81 cd/m2 (2 standard deviations)
Exposure value	–3.02 stops (aim for –2 to –3)
Exposure spread	3.02 stops
Area used for calculation	0.378 x 0.505
Camera settings	Exposure time: 1/10 ISO: 1600 F-number: 2.8 Focal length: 28.5 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	19 cd/m2
Luminance spread	5 cd/m2 (2 standard deviations)
Exposure value	–1.84 stops (aim for –2 to –3)
Exposure spread	0.38 stops
Area used for calculation	0.378 x 0.505
Camera settings	Exposure time: 1/8 ISO: 80 F-number: 2.8 Focal length: 28.5 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.