Contrast ratio results for HP Z Display

Contrast ratio 864:1
Monitor model HP Z Display
Submitted 01 Jan 2019 01:48 CET, by 84.1.*.*
Camera model Canon DIGITAL IXUS 870 IS
Processing remarks

image file 2: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time.
Warning: image file 2: Underexposed. Please increase the shutter time.
Note: image file 2: suggested exposure time: 1.4 s (Set EV to +1.5)

Black
Screen photo
Luminance 0.1 cd/m2
Luminance spread 0.1 cd/m2 (2 standard deviations)
Exposure value –4.03 stops   (aim for –2 to –3)
Exposure spread 1.46 stops
Area used for calculation 0.399 x 0.399
Camera settings Exposure time: 0.5   ISO: 800   F-number: 2.8
Focal length: 27.6 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
Luminance 89 cd/m2
Luminance spread 12 cd/m2 (2 standard deviations)
Exposure value –1.93 stops   (aim for –2 to –3)
Exposure spread 0.19 stops
Area used for calculation 0.399 x 0.399
Camera settings Exposure time: 1/403   ISO: 800   F-number: 2.8
Focal length: 27.6 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.