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

Contrast ratio results for Acer P221W

Contrast ratio 2045:1 (edge: 3683:1)
Monitor model Acer P221W
Submitted 12 Jan 2010 06:58 CET, by 24.16.*.*
Camera model Nikon COOLPIX S550
Processing remarks

Warning: image file 1: Underexposed. Please increase the shutter time.
Note: image file 1: suggested exposure time: 12.0 s (Set EV to +5.6)
image file 3: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time.
Warning: image file 3: Underexposed. Please increase the shutter time.
Note: image file 3: suggested exposure time: 21.6 s (Set EV to +6.4)

Black
Screen photo
[open image]
Luminance 0.08 cd/m2
Luminance spread 0.03 cd/m2 (2 standard deviations)
Exposure value –6.08 stops   (aim for –2 to –3)
Exposure spread 0.5 stops
Area used for calculation 0.52 x 0.52
Camera settings Exposure time: 1   ISO: 200   F-number: 3.5
Focal length: 36 mm   (35 mm equivalent)
Exposure compensation: 2
White
Screen photo
[open image]
Luminance 158 cd/m2
Luminance spread 22 cd/m2 (2 standard deviations)
Exposure value –1.48 stops   (aim for –2 to –3)
Exposure spread 0.2 stops
Area used for calculation 0.52 x 0.52
Camera settings Exposure time: 1/84   ISO: 200   F-number: 3.5
Focal length: 36 mm   (35 mm equivalent)
Exposure compensation: -0.3
Black at screen edge
Screen photo
[open image]
Luminance 0.04 cd/m2
Luminance spread 0.01 cd/m2 (2 standard deviations)
Exposure value –6.93 stops   (aim for –2 to –3)
Exposure spread 0.44 stops
Area used for calculation 0.52 x 0.52
Camera settings Exposure time: 1   ISO: 200   F-number: 3.5
Focal length: 36 mm   (35 mm equivalent)
Exposure compensation: 2

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.