Contrast ratio results for Dell

Black
Contrast ratio	991:1
Monitor model	Dell
Submitted	24 Apr 2013 15:20 CEST, by 46.194..
Camera model	Canon EOS 450D
Processing remarks	Warning: image file 1: Underexposed. Please increase the shutter time. Note: image file 1: suggested exposure time: 5.4 s (Set EV to +2.4) Note: image file 2: suggested exposure time: 1/180 s (Set EV to +1.1)
Screen photo	[open image]
Luminance	0.11 cd/m2
Luminance spread	0.09 cd/m2 (2 standard deviations)
Exposure value	–4.93 stops (aim for –2 to –3)
Exposure spread	1.16 stops
Area used for calculation	0.628 x 0.706
Camera settings	Exposure time: 1 ISO: 400 F-number: 4 Focal length: 45.2 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	111 cd/m2
Luminance spread	38 cd/m2 (2 standard deviations)
Exposure value	–3.6 stops (aim for –2 to –3)
Exposure spread	0.49 stops
Area used for calculation	0.628 x 0.706
Camera settings	Exposure time: 1/395 ISO: 400 F-number: 4 Focal length: 45.2 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.