Contrast ratio results for iPhone 4

Contrast ratio 488:1
Monitor model iPhone 4
Submitted 11 Sep 2011 15:31 CEST, by 90.213.*.*
Camera model Sony DSC-V3
Processing remarks

Note: image file 1: suggested exposure time: 4.6 s (Set EV to -1.1)
image file 2: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time.
Warning: image file 2: Underexposed. Please increase the shutter time.
Note: image file 2: suggested exposure time: 1/110 s (Set EV to +2.2)

Black
Screen photo
Luminance 0.06 cd/m2
Luminance spread 0.01 cd/m2 (2 standard deviations)
Exposure value –1.38 stops   (aim for –2 to –3)
Exposure spread 0.27 stops
Area used for calculation 0.49 x 0.49
Camera settings Exposure time: 10   ISO: 400   F-number: 2.8
Focal length: 33.9 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
Luminance 31 cd/m2
Luminance spread 12 cd/m2 (2 standard deviations)
Exposure value –4.73 stops   (aim for –2 to –3)
Exposure spread 0.57 stops
Area used for calculation 0.49 x 0.49
Camera settings Exposure time: 1/500   ISO: 400   F-number: 2.8
Focal length: 33.9 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.