Contrast ratio results for HP Z Display

Black
Contrast ratio	795:1
Monitor model	HP Z Display
Submitted	01 Jan 2019 02:19 CET, by 84.1..
Camera model	Pentax K-5 II s
Processing remarks	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	0.27 cd/m2
Luminance spread	0.2 cd/m2 (2 standard deviations)
Exposure value	–2.96 stops (aim for –2 to –3)
Exposure spread	1.09 stops
Area used for calculation	0.708 x 0.797
Camera settings	Exposure time: 2.5 ISO: 400 F-number: 5 Focal length: 51 mm (35 mm equivalent) Exposure compensation: 0
White
Screen photo	[open image]
Luminance	218 cd/m2
Luminance spread	62 cd/m2 (2 standard deviations)
Exposure value	–2.97 stops (aim for –2 to –3)
Exposure spread	0.41 stops
Area used for calculation	0.833 x 0.937
Camera settings	Exposure time: 1/320 ISO: 400 F-number: 5 Focal length: 60 mm (35 mm equivalent) Exposure compensation: 0
Black at screen edge
Screen photo	[open image]
Luminance	213 cd/m2
Luminance spread	59 cd/m2 (2 standard deviations)
Exposure value	–3 stops (aim for –2 to –3)
Exposure spread	0.41 stops
Area used for calculation	0.708 x 0.797
Camera settings	Exposure time: 1/320 ISO: 400 F-number: 5 Focal length: 51 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.