Contrast ratio results

Black
Contrast ratio	43:1
Monitor model
Submitted	24 Dec 2010 05:27 CET, by 92.47..
Camera model	Nikon D90
Processing remarks	image file 3: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time. Warning: image file 3 is too bright to be a dark photo. Maybe you mixed up the files?
Screen photo	[open image]
Luminance	5 cd/m2
Luminance spread	5 cd/m2 (2 standard deviations)
Exposure value	–2.06 stops (aim for –2 to –3)
Exposure spread	1.58 stops
Area used for calculation	1 x 1
Camera settings	Exposure time: 0.3 ISO: 400 F-number: 5.6 Focal length: 75 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	230 cd/m2
Luminance spread	51 cd/m2 (2 standard deviations)
Exposure value	–2.39 stops (aim for –2 to –3)
Exposure spread	0.32 stops
Area used for calculation	1 x 1
Camera settings	Exposure time: 1/180 ISO: 400 F-number: 5.6 Focal length: 75 mm (35 mm equivalent) Exposure compensation: 0
Black at screen edge
Screen photo	[open image]
Luminance	145 cd/m2
Luminance spread	206 cd/m2 (2 standard deviations)
Exposure value	–2.06 stops (aim for –2 to –3)
Exposure spread	2.57 stops
Area used for calculation	1 x 1
Camera settings	Exposure time: 1/90 ISO: 400 F-number: 5.6 Focal length: 75 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.