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Contrast ratio of Thinkpad T42 SXVGA 15"

Contrast ratio 340:1
Monitor model Thinkpad T42 SXVGA 15"
Submitted 01 Nov 2008 23:22 CET, by 76.200.*.*
Camera model Canon PowerShot SD750
Processing remarks


Black
Screen photo
[open image]
Luminance 0.23 cd/m2
Luminance spread 0.09 cd/m2 (2 standard deviations)
Exposure value –2.85 stops   (aim for –2 to –3)
Exposure spread 0.59 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
[open image]
Luminance 79 cd/m2
Luminance spread 25 cd/m2 (2 standard deviations)
Exposure value –1.76 stops   (aim for –2 to –3)
Exposure spread 0.46 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: 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.