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

Contrast ratio results for Samsung CF791

Contrast ratio 5026:1
Monitor model Samsung CF791
Submitted 18 Jan 2018 02:14 CET, by 24.162.*.*
Camera model Apple iPhone 6s
Processing remarks

Warning: image file 1: automatic white balance can cause inaccuracies.
image file 1: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time.
Warning: image file 1: Underexposed. Please increase the shutter time.
Note: image file 1: suggested exposure time: 0.4 s (Set EV to +2.4)
Warning: image file 2: automatic white balance can cause inaccuracies.
image file 2: Warning: image includes screen edges or something that's not a monitor. Hold the camera close to the screen.
Warning: image file 2: Overexposed. Please decrease the shutter time.
Note: image file 2: suggested exposure time: 1/180 s (Set EV to -2.2)
Warning: Image ISO settings are not the same.

Black
Screen photo
[open image]
Luminance 0.1 cd/m2
Luminance spread 0.08 cd/m2 (2 standard deviations)
Exposure value –4.89 stops   (aim for –2 to –3)
Exposure spread 1.1 stops
Area used for calculation 0.419 x 0.419
Camera settings Exposure time: 1/15   ISO: 2000   F-number: 2.2
Focal length: 29 mm   (35 mm equivalent)
Exposure compensation: 0
White
Screen photo
[open image]
Luminance 525 cd/m2
Luminance spread 84 cd/m2 (2 standard deviations)
Exposure value –0.34 stops   (aim for –2 to –3)
Exposure spread 0.23 stops
Area used for calculation 0.419 x 0.419
Camera settings Exposure time: 1/40   ISO: 25   F-number: 2.2
Focal length: 29 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.