Contrast ratio results

Black
Contrast ratio	4:1
Monitor model
Submitted	06 Dec 2010 16:11 CET, by 122.161..
Camera model	Nokia N79
Processing remarks	Warning: image file 1: could not determine angle of view; assuming 38 mm lens (35 mm equivalent). Note: image file 1: suggested exposure time: 1/79 s (Set EV to -1.7) Warning: image file 2: could not determine angle of view; assuming 38 mm lens (35 mm equivalent). Warning: image file 2: Overexposed. Please decrease the shutter time. Note: image file 2: suggested exposure time: 1/210 s (Set EV to -2.1) Warning: Image ISO settings are not the same.
Screen photo	[open image]
Luminance	47 cd/m2
Luminance spread	32 cd/m2 (2 standard deviations)
Exposure value	–0.83 stops (aim for –2 to –3)
Exposure spread	1.03 stops
Area used for calculation	0.528 x 0.528
Camera settings	Exposure time: 1/25 ISO: 200 F-number: 2.8 Focal length: 0 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	179 cd/m2
Luminance spread	42 cd/m2 (2 standard deviations)
Exposure value	–0.41 stops (aim for –2 to –3)
Exposure spread	0.34 stops
Area used for calculation	0.528 x 0.528
Camera settings	Exposure time: 1/50 ISO: 141 F-number: 2.8 Focal length: 0 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.