Contrast ratio results

Black
Contrast ratio	7:1
Monitor model
Submitted	17 Sep 2016 11:48 CEST, by 114.79..
Camera model	HTC Desire X dual sim
Processing remarks	Warning: using the flash makes no sense. Warning: image file 1: could not determine angle of view; assuming 38 mm lens (35 mm equivalent). 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: Overexposed. Please decrease the shutter time. Note: image file 1: suggested exposure time: 1/67 s (Set EV to -1.0) Warning: image file 2: could not determine angle of view; assuming 38 mm lens (35 mm equivalent). 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: could not determine angle of view; assuming 38 mm lens (35 mm equivalent). 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. Note: image file 3: suggested exposure time: 1/12 s (Set EV to +1.1) 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	7 cd/m2
Luminance spread	1 cd/m2 (2 standard deviations)
Exposure value	–2.83 stops (aim for –2 to –3)
Exposure spread	0.13 stops
Area used for calculation	0.528 x 0.237
Camera settings	Exposure time: 1/25 ISO: 177 F-number: 2 Focal length: 0 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	49 cd/m2
Luminance spread	56 cd/m2 (2 standard deviations)
Exposure value	–1.47 stops (aim for –2 to –3)
Exposure spread	1.91 stops
Area used for calculation	0.528 x 0.661
Camera settings	Exposure time: 1/33 ISO: 84 F-number: 2 Focal length: 0 mm (35 mm equivalent) Exposure compensation: 0
Black at screen edge
Screen photo	[open image]
Luminance	22 cd/m2
Luminance spread	79 cd/m2 (2 standard deviations)
Exposure value	–3.61 stops (aim for –2 to –3)
Exposure spread	4.25 stops
Area used for calculation	0.528 x 0.528
Camera settings	Exposure time: 1/25 ISO: 61 F-number: 2.8 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.