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

Contrast ratio results

Contrast ratio 4:1
Monitor model
Submitted 25 Nov 2012 20:10 CET, by 77.182.*.*
Camera model Sony SLT-A57
Processing remarks

Warning: image file 1: automatic white balance can cause inaccuracies.
Note: image file 1: suggested exposure time: 1/230 s (Set EV to -2.0)
Warning: image file 2: automatic white balance can cause inaccuracies.
Warning: image file 2: Overexposed. Please decrease the shutter time.
Warning: image file 3: automatic white balance can cause inaccuracies.
Note: image file 3: suggested exposure time: 1/230 s (Set EV to -2.0)
Warning: image file 3 is too bright to be a dark photo. Maybe you mixed up the files?

Black
Screen photo
[open image]
Luminance 28 cd/m2
Luminance spread 3 cd/m2 (2 standard deviations)
Exposure value –0.55 stops   (aim for –2 to –3)
Exposure spread 0.14 stops
Area used for calculation 0.721 x 0.815
Camera settings Exposure time: 1/60   ISO: 400   F-number: 1.8
Focal length: 52 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
[open image]
Luminance 126 cd/m2
Luminance spread 16 cd/m2 (2 standard deviations)
Exposure value –0.46 stops   (aim for –2 to –3)
Exposure spread 0.19 stops
Area used for calculation 0.721 x 0.815
Camera settings Exposure time: 1/250   ISO: 400   F-number: 1.8
Focal length: 52 mm   (35 mm equivalent)
Exposure compensation: 0
Black at screen edge
Screen photo
[open image]
Luminance 28 cd/m2
Luminance spread 3 cd/m2 (2 standard deviations)
Exposure value –0.55 stops   (aim for –2 to –3)
Exposure spread 0.14 stops
Area used for calculation 0.721 x 0.815
Camera settings Exposure time: 1/60   ISO: 400   F-number: 1.8
Focal length: 52 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.