Contrast ratio results for BenQ 2420

Black
Contrast ratio	2242:1 (edge: 1946:1)
Monitor model	BenQ 2420
Submitted	11 Jan 2015 16:52 CET, by 86.19..
Camera model	LGE Nexus 4
Processing remarks	Warning: image file 1: could not determine angle of view; assuming 38 mm lens (35 mm equivalent). 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: 3.8 s (Set EV to +5.6) Warning: image file 2: could not determine angle of view; assuming 38 mm lens (35 mm equivalent). image file 2: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time. Warning: image file 3: could not determine angle of view; assuming 38 mm lens (35 mm equivalent). Warning: image file 3: Underexposed. Please increase the shutter time. Note: image file 3: suggested exposure time: 3.3 s (Set EV to +5.4) Warning: Image ISO settings are not the same.
Screen photo	[open image]
Luminance	0.02 cd/m2
Luminance spread	0.03 cd/m2 (2 standard deviations)
Exposure value	–8.14 stops (aim for –2 to –3)
Exposure spread	4.25 stops
Area used for calculation	0.528 x 0.528
Camera settings	Exposure time: 1/13 ISO: 1600 F-number: 2.5 Focal length: 0 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	34 cd/m2
Luminance spread	16 cd/m2 (2 standard deviations)
Exposure value	–2.22 stops (aim for –2 to –3)
Exposure spread	0.7 stops
Area used for calculation	0.528 x 0.528
Camera settings	Exposure time: 1/30 ISO: 100 F-number: 2.5 Focal length: 0 mm (35 mm equivalent) Exposure compensation: 0
Black at screen edge
Screen photo	[open image]
Luminance	0.02 cd/m2
Luminance spread	0.04 cd/m2 (2 standard deviations)
Exposure value	–7.94 stops (aim for –2 to –3)
Exposure spread	4.25 stops
Area used for calculation	0.528 x 0.528
Camera settings	Exposure time: 1/13 ISO: 1600 F-number: 2.5 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.