Contrast ratio results

Black
Contrast ratio	3:1
Monitor model
Submitted	09 Dec 2016 18:23 CET, by 73.155..
Camera model	Apple iPhone 6s
Processing remarks	Warning: image file 1: exposure time below 1/500 sec is unreliable. Try increasing the EV compensation. 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: Overexposed. Please decrease the shutter time. 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.
Screen photo	[open image]
Luminance	800 cd/m2
Luminance spread	951 cd/m2 (2 standard deviations)
Exposure value	–1.75 stops (aim for –2 to –3)
Exposure spread	1.98 stops
Area used for calculation	0.419 x 0.419
Camera settings	Exposure time: 1/163 ISO: 25 F-number: 2.2 Focal length: 29 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	2745 cd/m2
Luminance spread	5325 cd/m2 (2 standard deviations)
Exposure value	–2.09 stops (aim for –2 to –3)
Exposure spread	4.25 stops
Area used for calculation	0.419 x 0.419
Camera settings	Exposure time: 1/705 ISO: 25 F-number: 2.2 Focal length: 29 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.