| Contrast ratio | 451:1 |
|---|---|
| Monitor model | |
| Submitted | 07 Jan 2009 19:44 CET, by 85.140.*.* |
| Camera model | Pentax Optio A20 |
| Processing remarks | image file 1: Note: image seems to be noisy. Try reducing the ISO setting or increasing the exposure time. |
| Black | |
| Screen photo |
|
| Luminance | 0.15 cd/m2 |
| Luminance spread | 0.02 cd/m2 (2 standard deviations) |
| Exposure value | –3.07 stops (aim for –2 to –3) |
| Exposure spread | 0.19 stops |
| Area used for calculation | 0.549 x 0.549 |
| Camera settings | Exposure time: 1.3 ISO: 400 F-number: 2.8 Focal length: 38 mm (35 mm equivalent) Exposure compensation: 0 |
| White | |
| Screen photo |
|
| Luminance | 69 cd/m2 |
| Luminance spread | 18 cd/m2 (2 standard deviations) |
| Exposure value | –3.28 stops (aim for –2 to –3) |
| Exposure spread | 0.39 stops |
| Area used for calculation | 0.549 x 0.549 |
| Camera settings | Exposure time: 1/400 ISO: 400 F-number: 2.8 Focal length: 38 mm (35 mm equivalent) Exposure compensation: 0 |
![[open image]](upload/cr004/01022a.jpg){kind=link}
![[open image]](upload/cr004/01022b.jpg){kind=link}
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.