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

Contrast ratio results for Lenovo T420 screen

Contrast ratio 163:1
Monitor model Lenovo T420 screen
Submitted 06 Sep 2018 22:26 CEST, by 128.68.*.*
Camera model Nikon COOLPIX P330
Processing remarks

image file 1: Warning: image includes screen edges or something that's not a monitor. Hold the camera close to the screen.
image file 2: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time.

Black
Screen photo
[open image]
Luminance 0.92 cd/m2
Luminance spread 1.22 cd/m2 (2 standard deviations)
Exposure value –1.59 stops   (aim for –2 to –3)
Exposure spread 2.3 stops
Area used for calculation 0.347 x 0.347
Camera settings Exposure time: 0.5   ISO: 200   F-number: 1.8
Focal length: 24 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
[open image]
Luminance 150 cd/m2
Luminance spread 31 cd/m2 (2 standard deviations)
Exposure value –1.88 stops   (aim for –2 to –3)
Exposure spread 0.3 stops
Area used for calculation 0.347 x 0.347
Camera settings Exposure time: 1/400   ISO: 200   F-number: 1.8
Focal length: 24 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.