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

Contrast ratio results

Contrast ratio 6617:1
Monitor model
Submitted 08 Nov 2010 13:20 CET, by 89.136.*.*
Camera model Canon PowerShot A430
Processing remarks

image file 1: Warning: image includes screen edges or something that's not a monitor. Hold the camera close to the screen.
Warning: image file 1: Underexposed. Please increase the shutter time.
Note: image file 1: suggested exposure time: 9.0 s (Set EV to +3.2)

Black
Screen photo
[open image]
Luminance 0.03 cd/m2
Luminance spread 0.02 cd/m2 (2 standard deviations)
Exposure value –5.67 stops   (aim for –2 to –3)
Exposure spread 0.88 stops
Area used for calculation 0.553 x 0.553
Camera settings Exposure time: 1   ISO: 400   F-number: 2.8
Focal length: 38.3 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
[open image]
Luminance 218 cd/m2
Luminance spread 30 cd/m2 (2 standard deviations)
Exposure value –1.94 stops   (aim for –2 to –3)
Exposure spread 0.2 stops
Area used for calculation 0.553 x 0.553
Camera settings Exposure time: 1/501   ISO: 400   F-number: 2.8
Focal length: 38.3 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.