Contrast ratio results

Black
Contrast ratio	3:1
Monitor model
Submitted	22 Jul 2021 20:17 CEST, by 42.112..
Camera model	Apple iPhone 7 Plus
Processing remarks	image file 1: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time. 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. Note: image file 2: suggested exposure time: 1/170 s (Set EV to -2.5) Warning: Image ISO settings are not the same.
Screen photo	[open image]
Luminance	406 cd/m2
Luminance spread	23 cd/m2 (2 standard deviations)
Exposure value	–0.03 stops (aim for –2 to –3)
Exposure spread	0.08 stops
Area used for calculation	0.371 x 0.495
Camera settings	Exposure time: 1/30 ISO: 20 F-number: 1.8 Focal length: 28 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	1244 cd/m2
Luminance spread	161 cd/m2 (2 standard deviations)
Exposure value	–0.83 stops (aim for –2 to –3)
Exposure spread	0.19 stops
Area used for calculation	0.371 x 0.495
Camera settings	Exposure time: 1/200 ISO: 25 F-number: 1.8 Focal length: 28 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.