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

Contrast ratio results for dell latitude d820 laptop screen

Contrast ratio 543:1 (edge: 607:1)
Monitor model dell latitude d820 laptop screen
Submitted 02 Jun 2008 13:57 CEST, by 83.5.*.*
Camera model Canon PowerShot A630
Processing remarks

image file 1: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time.
Note: image file 1: suggested exposure time: 2.7 s (Set EV to +1.1)
image file 2: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time.
image file 3: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time.
Note: image file 3: suggested exposure time: 3.0 s (Set EV to +1.2)
Warning: Image F-number settings are not the same.

Black
Screen photo
[open image]
Luminance 0.17 cd/m2
Luminance spread 0.04 cd/m2 (2 standard deviations)
Exposure value –3.55 stops   (aim for –2 to –3)
Exposure spread 0.34 stops
Area used for calculation 0.49 x 0.49
Camera settings Exposure time: 1.3   ISO: 408   F-number: 3.5
Focal length: 33.9 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
[open image]
Luminance 91 cd/m2
Luminance spread 56 cd/m2 (2 standard deviations)
Exposure value –2.86 stops   (aim for –2 to –3)
Exposure spread 0.92 stops
Area used for calculation 0.49 x 0.49
Camera settings Exposure time: 1/403   ISO: 408   F-number: 2.8
Focal length: 33.9 mm   (35 mm equivalent)
Exposure compensation: 0
Black at screen edge
Screen photo
[open image]
Luminance 0.15 cd/m2
Luminance spread 0.05 cd/m2 (2 standard deviations)
Exposure value –3.71 stops   (aim for –2 to –3)
Exposure spread 0.53 stops
Area used for calculation 0.49 x 0.49
Camera settings Exposure time: 1.3   ISO: 408   F-number: 3.5
Focal length: 33.9 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.