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

Contrast ratio results

Contrast ratio 677:1
Monitor model
Submitted 22 Mar 2009 13:44 CET, by 62.63.*.*
Camera model Canon PowerShot A590 IS
Processing remarks

Note: image file 1: suggested exposure time: 4.2 s (Set EV to +1.4)

Black
Screen photo
[open image]
Luminance 0.12 cd/m2
Luminance spread 0.06 cd/m2 (2 standard deviations)
Exposure value –3.88 stops   (aim for –2 to –3)
Exposure spread 0.67 stops
Area used for calculation 0.495 x 0.495
Camera settings Exposure time: 1.6   ISO: 200   F-number: 2.6
Focal length: 34.3 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
[open image]
Luminance 83 cd/m2
Luminance spread 7 cd/m2 (2 standard deviations)
Exposure value –1.81 stops   (aim for –2 to –3)
Exposure spread 0.12 stops
Area used for calculation 0.495 x 0.495
Camera settings Exposure time: 1/101   ISO: 200   F-number: 2.6
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.