Contrast ratio results

Contrast ratio 616:1
Monitor model
Submitted 19 Jun 2011 14:30 CEST, by 195.130.*.*
Camera model Canon EOS REBEL T1i
Processing remarks

Warning: image file 1: camera was zoomed in too much.
Note: image file 1: suggested exposure time: 2.2 s (Set EV to +1.1)
Warning: image file 2: camera was zoomed in too much.
Warning: image file 3: camera was zoomed in too much.
image file 3: Warning: image includes screen edges or something that's not a monitor. Hold the camera close to the screen.
Warning: image file 3: Overexposed. Please decrease the shutter time.
Note: image file 3: suggested exposure time: 1/69 s (Set EV to -1.5)
Warning: image file 3 is too bright to be a dark photo. Maybe you mixed up the files?

Black
Screen photo
Luminance 0.21 cd/m2
Luminance spread 0.26 cd/m2 (2 standard deviations)
Exposure value –3.63 stops   (aim for –2 to –3)
Exposure spread 2.07 stops
Area used for calculation 1 x 1
Camera settings Exposure time: 1   ISO: 400   F-number: 3.5
Focal length: 114 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
Luminance 130 cd/m2
Luminance spread 75 cd/m2 (2 standard deviations)
Exposure value –2.99 stops   (aim for –2 to –3)
Exposure spread 0.86 stops
Area used for calculation 1 x 1
Camera settings Exposure time: 1/395   ISO: 400   F-number: 3.5
Focal length: 114 mm   (35 mm equivalent)
Exposure compensation: 0
Black at screen edge
Screen photo
Luminance 32 cd/m2
Luminance spread 64 cd/m2 (2 standard deviations)
Exposure value –1.03 stops   (aim for –2 to –3)
Exposure spread 4.25 stops
Area used for calculation 1 x 1
Camera settings Exposure time: 1/25   ISO: 400   F-number: 3.5
Focal length: 114 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.