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

Contrast ratio results for Dell u221h

Contrast ratio 438:1
Monitor model Dell u221h
Submitted 06 Jan 2012 06:06 CET, by 96.247.*.*
Camera model Apple iPhone 4S
Processing remarks

Warning: image file 1: automatic white balance can cause inaccuracies.
Warning: image file 1: Underexposed. Please increase the shutter time.
Note: image file 1: suggested exposure time: 4.3 s (Set EV to +6.4)
Warning: image file 2: automatic white balance can cause inaccuracies.
Warning: image file 2: Overexposed. Please decrease the shutter time.
Note: image file 2: suggested exposure time: 1/100 s (Set EV to -2.4)

Black
Screen photo
[open image]
Luminance 0.16 cd/m2
Luminance spread 0.04 cd/m2 (2 standard deviations)
Exposure value –8.92 stops   (aim for –2 to –3)
Exposure spread 0.4 stops
Area used for calculation 0.485 x 0.55
Camera settings Exposure time: 1/20   ISO: 125   F-number: 2.4
Focal length: 35 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
[open image]
Luminance 71 cd/m2
Luminance spread 5 cd/m2 (2 standard deviations)
Exposure value –0.15 stops   (aim for –2 to –3)
Exposure spread 0.1 stops
Area used for calculation 0.48 x 0.565
Camera settings Exposure time: 1/20   ISO: 125   F-number: 2.4
Focal length: 35 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.