Contrast ratio results

Contrast ratio 145:1
Monitor model
Submitted 08 May 2011 01:08 CEST, by 132.155.*.*
Camera model Canon EOS 40D
Processing remarks

Warning: image file 2: camera was zoomed in too much.
Warning: Image focal lengths/zoom levels are not the same.

Black
Screen photo
Luminance 1.5 cd/m2
Luminance spread 2.68 cd/m2 (2 standard deviations)
Exposure value –2.16 stops   (aim for –2 to –3)
Exposure spread 4.17 stops
Area used for calculation 0.472 x 0.532
Camera settings Exposure time: 1/4   ISO: 400   F-number: 2.8
Focal length: 34 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
Luminance 217 cd/m2
Luminance spread 80 cd/m2 (2 standard deviations)
Exposure value –1.61 stops   (aim for –2 to –3)
Exposure spread 0.54 stops
Area used for calculation 1 x 1
Camera settings Exposure time: 1/395   ISO: 400   F-number: 2.8
Focal length: 81 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.