Contrast ratio results

Contrast ratio 1509:1
Monitor model
Submitted 07 Dec 2012 22:49 CET, by 46.236.*.*
Camera model Pentax K-x
Processing remarks

Warning: image file 1: Underexposed. Please increase the shutter time.
Note: image file 1: suggested exposure time: 3.9 s (Set EV to +2.0)

Black
Screen photo
Luminance 0.06 cd/m2
Luminance spread 0.02 cd/m2 (2 standard deviations)
Exposure value –4.47 stops   (aim for –2 to –3)
Exposure spread 0.44 stops
Area used for calculation 0.375 x 0.422
Camera settings Exposure time: 1   ISO: 800   F-number: 3.5
Focal length: 27 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
Luminance 89 cd/m2
Luminance spread 21 cd/m2 (2 standard deviations)
Exposure value –2.55 stops   (aim for –2 to –3)
Exposure spread 0.34 stops
Area used for calculation 0.375 x 0.422
Camera settings Exposure time: 1/400   ISO: 800   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.