Contrast ratio results

Contrast ratio 727:1
Monitor model
Submitted 02 Nov 2008 05:48 CET, by 76.200.*.*
Camera model Canon PowerShot SD750
Processing remarks

Warning: image file 1: automatic white balance can cause inaccuracies.
Warning: image file 2: automatic white balance can cause inaccuracies.
Warning: image file 2: Overexposed. Please decrease the shutter time.

Black
Screen photo
Luminance 0.28 cd/m2
Luminance spread 0.23 cd/m2 (2 standard deviations)
Exposure value –2.58 stops   (aim for –2 to –3)
Exposure spread 1.26 stops
Area used for calculation 0.495 x 0.495
Camera settings Exposure time: 1   ISO: 400   F-number: 2.8
Focal length: 34.3 mm   (35 mm equivalent)
Exposure compensation: 4
White
Screen photo
Luminance 204 cd/m2
Luminance spread 32 cd/m2 (2 standard deviations)
Exposure value –0.39 stops   (aim for –2 to –3)
Exposure spread 0.23 stops
Area used for calculation 0.495 x 0.495
Camera settings Exposure time: 1/159   ISO: 400   F-number: 2.8
Focal length: 34.3 mm   (35 mm equivalent)
Exposure compensation: 4

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.