| Contrast ratio | 735:1 |
|---|---|
| Monitor model | xt |
| Submitted | 16 Dec 2009 05:12 CET, by 69.145.*.* |
| Camera model | Canon PowerShot A620 |
| Processing remarks | Warning: image file 2: exposure time below 1/500 sec is unreliable. Try increasing the EV compensation. |
| Black | |
| Screen photo |
|
| Luminance | 0.62 cd/m2 |
| Luminance spread | 0.1 cd/m2 (2 standard deviations) |
| Exposure value | –1.77 stops (aim for –2 to –3) |
| Exposure spread | 0.24 stops |
| Area used for calculation | 0.494 x 0.494 |
| Camera settings | Exposure time: 0.8 ISO: 400 F-number: 2.8 Focal length: 34.2 mm (35 mm equivalent) Exposure compensation: 0 |
| White | |
| Screen photo |
|
| Luminance | 453 cd/m2 |
| Luminance spread | 172 cd/m2 (2 standard deviations) |
| Exposure value | –1.58 stops (aim for –2 to –3) |
| Exposure spread | 0.56 stops |
| Area used for calculation | 0.494 x 0.494 |
| Camera settings | Exposure time: 1/807 ISO: 400 F-number: 2.8 Focal length: 34.2 mm (35 mm equivalent) Exposure compensation: 0 |
![[open image]](upload/cr008/02157a.jpg){kind=link}
![[open image]](upload/cr008/02157b.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.