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

Contrast ratio results

Contrast ratio 4700:1
Monitor model
Submitted 21 May 2011 15:15 CEST, by 59.167.*.*
Camera model Canon PowerShot A720 IS
Processing remarks

image file 2: Warning: image includes screen edges or something that's not a monitor. Hold the camera close to the screen.

Black
Screen photo
[open image]
Luminance 0.08 cd/m2
Luminance spread 0.08 cd/m2 (2 standard deviations)
Exposure value –2.82 stops   (aim for –2 to –3)
Exposure spread 1.64 stops
Area used for calculation 0.495 x 0.495
Camera settings Exposure time: 15   ISO: 80   F-number: 2.8
Focal length: 34.3 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
[open image]
Luminance 372 cd/m2
Luminance spread 202 cd/m2 (2 standard deviations)
Exposure value –3.18 stops   (aim for –2 to –3)
Exposure spread 0.8 stops
Area used for calculation 0.495 x 0.495
Camera settings Exposure time: 1/403   ISO: 80   F-number: 2.8
Focal length: 34.3 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.