Contrast ratio of iMac 21"

Contrast ratio 707:1
Monitor model iMac 21"
Submitted 01 Sep 2011 20:22 CEST, by 85.180.*.*
Camera model Nikon D40
Processing remarks


Black
Screen photo
Luminance 0.25 cd/m2
Luminance spread 0.06 cd/m2 (2 standard deviations)
Exposure value –1.79 stops   (aim for –2 to –3)
Exposure spread 0.37 stops
Area used for calculation 0.375 x 0.423
Camera settings Exposure time: 3   ISO: 400   F-number: 3.5
Focal length: 27 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
Luminance 178 cd/m2
Luminance spread 17 cd/m2 (2 standard deviations)
Exposure value –1.56 stops   (aim for –2 to –3)
Exposure spread 0.14 stops
Area used for calculation 0.375 x 0.423
Camera settings Exposure time: 1/200   ISO: 400   F-number: 3.5
Focal length: 27 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.