Contrast ratio results for BenQ 2420

Black
Contrast ratio	1034:1
Monitor model	BenQ 2420
Submitted	11 Jan 2015 16:50 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: 1.7 s (Set EV to +4.4) Warning: image file 2: could not determine angle of view; assuming 38 mm lens (35 mm equivalent). Warning: Image ISO settings are not the same.
Screen photo	[open image]
Luminance	0.04 cd/m2
Luminance spread	0.07 cd/m2 (2 standard deviations)
Exposure value	–6.93 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	37 cd/m2
Luminance spread	17 cd/m2 (2 standard deviations)
Exposure value	–2.12 stops (aim for –2 to –3)
Exposure spread	0.68 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

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.