Contrast ratio results

Black
Contrast ratio	57:1
Monitor model
Submitted	13 Sep 2011 08:14 CEST, by 15.211..
Camera model	Nikon D300
Processing remarks	Warning: image file 1: automatic white balance can cause inaccuracies. image file 1: Warning: image includes screen edges or something that's not a monitor. Hold the camera close to the screen. Warning: image file 1: Underexposed. Please increase the shutter time. Note: image file 1: suggested exposure time: 1/40 s (Set EV to +1.6) Warning: image file 2: camera was zoomed in too much. 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 2: Overexposed. Please decrease the shutter time. 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: Overexposed. Please decrease the shutter time. Warning: Image ISO settings are not the same. Warning: Image F-number settings are not the same. Warning: Images were taken with different cameras. Warning: Image focal lengths/zoom levels are not the same. Warning: image file 3 is too bright to be a dark photo. Maybe you mixed up the files?
Screen photo	[open image]
Luminance	3.78 cd/m2
Luminance spread	23.42 cd/m2 (2 standard deviations)
Exposure value	–4.14 stops (aim for –2 to –3)
Exposure spread	4.25 stops
Area used for calculation	0.995 x 1
Camera settings	Exposure time: 1/125 ISO: 640 F-number: 2 Focal length: 75 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	216 cd/m2
Luminance spread	235 cd/m2 (2 standard deviations)
Exposure value	–0.63 stops (aim for –2 to –3)
Exposure spread	1.76 stops
Area used for calculation	1 x 0.941
Camera settings	Exposure time: 1/400 ISO: 200 F-number: 1.4 Focal length: 127 mm (35 mm equivalent) Exposure compensation: 0
Black at screen edge
Screen photo	[open image]
Luminance	289 cd/m2
Luminance spread	671 cd/m2 (2 standard deviations)
Exposure value	–2.24 stops (aim for –2 to –3)
Exposure spread	4.25 stops
Area used for calculation	0.839 x 0.73
Camera settings	Exposure time: 1/200 ISO: 200 F-number: 4 Focal length: 55 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.