Contrast ratio results

Black
Contrast ratio	99:1
Monitor model
Submitted	24 Jan 2012 16:13 CET, by 115.143..
Camera model	Sony DSLR-A200
Processing remarks	Warning: image file 1: automatic white balance can cause inaccuracies. image file 1: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time. Warning: image file 1: Underexposed. Please increase the shutter time. Note: image file 1: suggested exposure time: 1.5 s (Set EV to +7.6) Warning: image file 2: automatic white balance can cause inaccuracies. image file 2: Warning: image includes screen edges or something that's not a monitor. Hold the camera close to the screen. Warning: image file 3: automatic white balance can cause inaccuracies. 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 is too bright to be a dark photo. Maybe you mixed up the files?
Screen photo	[open image]
Luminance	1.22 cd/m2
Luminance spread	15.2 cd/m2 (2 standard deviations)
Exposure value	–10.09 stops (aim for –2 to –3)
Exposure spread	4.25 stops
Area used for calculation	0.723 x 0.81
Camera settings	Exposure time: 1/125 ISO: 200 F-number: 5 Focal length: 52 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	122 cd/m2
Luminance spread	116 cd/m2 (2 standard deviations)
Exposure value	–2.4 stops (aim for –2 to –3)
Exposure spread	1.5 stops
Area used for calculation	0.723 x 0.81
Camera settings	Exposure time: 1/60 ISO: 200 F-number: 5 Focal length: 52 mm (35 mm equivalent) Exposure compensation: 0
Black at screen edge
Screen photo	[open image]
Luminance	62 cd/m2
Luminance spread	149 cd/m2 (2 standard deviations)
Exposure value	–3.38 stops (aim for –2 to –3)
Exposure spread	4.25 stops
Area used for calculation	0.723 x 0.81
Camera settings	Exposure time: 1/60 ISO: 200 F-number: 5 Focal length: 52 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.