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Contrast ratio results for System76 Gazelle Professional

Contrast ratio 677:1
Monitor model System76 Gazelle Professional
Submitted 25 Aug 2012 15:49 CEST, by 67.242.*.*
Camera model Canon PowerShot SD790 IS
Processing remarks

Warning: image file 1: automatic white balance can cause inaccuracies.
Warning: image file 2: automatic white balance can cause inaccuracies.

Black
Screen photo
[open image]
Luminance 0.22 cd/m2
Luminance spread 0.11 cd/m2 (2 standard deviations)
Exposure value –3.22 stops   (aim for –2 to –3)
Exposure spread 0.7 stops
Area used for calculation 0.494 x 0.494
Camera settings Exposure time: 0.8   ISO: 400   F-number: 2.8
Focal length: 34.2 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
[open image]
Luminance 152 cd/m2
Luminance spread 17 cd/m2 (2 standard deviations)
Exposure value –1.81 stops   (aim for –2 to –3)
Exposure spread 0.17 stops
Area used for calculation 0.494 x 0.494
Camera settings Exposure time: 1/318   ISO: 400   F-number: 2.8
Focal length: 34.2 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.