Contrast ratio | Test results | LCD test | Small-screen tests | Lagom home

Contrast ratio results

Contrast ratio 166:1
Monitor model
Submitted 13 Oct 2018 14:52 CEST, by 188.37.*.*
Camera model Microsoft Lumia 640 LTE
Processing remarks

Warning: image file 2: Overexposed. Please decrease the shutter time.
Note: image file 2: suggested exposure time: 1/91 s (Set EV to -2.2)

Black
Screen photo
[open image]
Luminance 0.63 cd/m2
Luminance spread 0.48 cd/m2 (2 standard deviations)
Exposure value –3.36 stops   (aim for –2 to –3)
Exposure spread 1.16 stops
Area used for calculation 0.404 x 0.404
Camera settings Exposure time: 1   ISO: 64   F-number: 2.2
Focal length: 28 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
[open image]
Luminance 104 cd/m2
Luminance spread 16 cd/m2 (2 standard deviations)
Exposure value –0.31 stops   (aim for –2 to –3)
Exposure spread 0.22 stops
Area used for calculation 0.404 x 0.404
Camera settings Exposure time: 1/20   ISO: 64   F-number: 2.2
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.