Using fluorescent lighting can cause colored bands, splotches, or flickering video that may scroll on the screen. All WDR cameras using multiple exposures, like Sure Vision, may be susceptible to these distortions when installed in areas with older technology lighting systems.
- Sarix Sureversion Cameras = All Models.
Within North America, a 60Hz current powers each camera, while Europe uses a 50Hz current. If you do a quick calculation, you'll notice that NTSC runs at 30 ips (Images per second) and PAL runs at 25 ips. The frame rate is directly tied to the electrical current. In simpler terms, when you turn on your camera, it begins its frame rate. This frame rate begins at a different time than the current rate of your fluorescent lighting. The fraction of a second difference causes the distortion to appear.
There are a few options:
- Change the lighting.
- Change the field of view of the camera so that incompatible light frequency sources are not shown in the scene.
- Open a web browser and set the Image Rate so that the lighting frequency is an exact multiple of the image rate:
D. Open a web browser and set the Day Max Exposure Time to a slightly lower value to optimize against flicker:
- For 60Hz – about 17 or 18 msec
- For 50Hz – about 21 or 22 msec
- On the IM domes try using a smoked dome.
- On the IX series, try using a 3rd party manual iris lens.
- Turn Flicker Correction to “on”.
To Turn on Flicker Correction:
- Use a web browser, and type in the IP address of the camera.
- Login and click on SETTINGS.
- Hover the mouse over the imaging TAB and select Exposure.
- Turn Flicker Correction to on.
Auto: This setting automatically reduces rolling shutter flicker in scenes with less dynamic range, but it does not reduce picture flicker in scenes with high dynamic range.
On: This setting reduces rolling shutter picture flicker, and it dramatically reduces the amount of dynamic range in the image.
Off: This setting maintains the maximum amount of dynamic range in the image, but it can produce rolling shutter picture flicker in scenes with fluorescent or other oscillating light sources. Off is the default setting.