Contrast ratio results

Contrast ratio 2246:1
Monitor model
Submitted 07 Jan 2009 19:58 CET, by 85.140.*.*
Camera model Pentax Optio A20
Processing remarks


Black
Screen photo
Luminance 0.2 cd/m2
Luminance spread 0.04 cd/m2 (2 standard deviations)
Exposure value –2.68 stops   (aim for –2 to –3)
Exposure spread 0.29 stops
Area used for calculation 0.549 x 0.549
Camera settings Exposure time: 1.3   ISO: 400   F-number: 2.8
Focal length: 38 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
Luminance 451 cd/m2
Luminance spread 45 cd/m2 (2 standard deviations)
Exposure value –0.57 stops   (aim for –2 to –3)
Exposure spread 0.15 stops
Area used for calculation 0.549 x 0.549
Camera settings Exposure time: 1/400   ISO: 400   F-number: 2.8
Focal length: 38 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.