Contrast ratio results

Contrast ratio 621:1
Monitor model
Submitted 19 Feb 2010 22:54 CET, by 85.204.*.*
Camera model Canon PowerShot A720 IS
Processing remarks


Black
Screen photo
Luminance 0.22 cd/m2
Luminance spread 0.05 cd/m2 (2 standard deviations)
Exposure value –3.26 stops   (aim for –2 to –3)
Exposure spread 0.32 stops
Area used for calculation 0.495 x 0.495
Camera settings Exposure time: 8   ISO: 80   F-number: 4
Focal length: 34.3 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
Luminance 139 cd/m2
Luminance spread 13 cd/m2 (2 standard deviations)
Exposure value –2.89 stops   (aim for –2 to –3)
Exposure spread 0.13 stops
Area used for calculation 0.495 x 0.495
Camera settings Exposure time: 1/60   ISO: 80   F-number: 4
Focal length: 34.3 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.