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Contrast ratio results for DELL XPS 1640

Contrast ratio 640:1
Monitor model DELL XPS 1640
Submitted 05 Sep 2010 00:48 CEST, by 201.148.*.*
Camera model Canon PowerShot SX120 IS
Processing remarks

Note: image file 1: suggested exposure time: 0.7 s (Set EV to +1.3)
Warning: image file 2: automatic white balance can cause inaccuracies.

Black
Screen photo
[open image]
Luminance 0.4 cd/m2
Luminance spread 0.15 cd/m2 (2 standard deviations)
Exposure value –3.81 stops   (aim for –2 to –3)
Exposure spread 0.54 stops
Area used for calculation 0.508 x 0.508
Camera settings Exposure time: 0.3   ISO: 400   F-number: 2.8
Focal length: 35.2 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
[open image]
Luminance 255 cd/m2
Luminance spread 31 cd/m2 (2 standard deviations)
Exposure value –1.41 stops   (aim for –2 to –3)
Exposure spread 0.18 stops
Area used for calculation 0.508 x 0.508
Camera settings Exposure time: 1/403   ISO: 400   F-number: 2.8
Focal length: 35.2 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.