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

Contrast ratio results

Contrast ratio 439:1
Monitor model
Submitted 05 Oct 2008 23:58 CEST, by 200.55.*.*
Camera model Canon PowerShot S5 IS
Processing remarks

Warning: image file 1: Underexposed. Please increase the shutter time.
Note: image file 1: suggested exposure time: 21.0 s (Set EV to +4.4)
image file 2: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time.
Warning: image file 2: Underexposed. Please increase the shutter time.
Note: image file 2: suggested exposure time: 1/100 s (Set EV to +1.9)
Warning: Image ISO settings are not the same.

Black
Screen photo
[open image]
Luminance 0.07 cd/m2
Luminance spread 0.02 cd/m2 (2 standard deviations)
Exposure value –6.9 stops   (aim for –2 to –3)
Exposure spread 0.44 stops
Area used for calculation 0.513 x 0.513
Camera settings Exposure time: 1   ISO: 80   F-number: 2.7
Focal length: 35.5 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
[open image]
Luminance 29 cd/m2
Luminance spread 16 cd/m2 (2 standard deviations)
Exposure value –4.45 stops   (aim for –2 to –3)
Exposure spread 0.8 stops
Area used for calculation 0.513 x 0.513
Camera settings Exposure time: 1/403   ISO: 400   F-number: 2.7
Focal length: 35.5 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.