Beware of fishy details
Editor / Provider: Tevin Wang, a&s International | Updated: 5/17/2013 | Article type: Tech Corner
Fisheye cameras provide views from all angles, but must be set up properly to be effective. This feature takes a closer look at practical expectations and tips.
Fisheye cameras are all about seeing everything in a scene more efficiently and effectively than with multiple cameras. They are also more economical as they reduce licensing costs by requiring only one license instead of multiple camera licenses to cover the same area. By expanding horizontally, fisheye cameras allow security managers to cover an entire scene in a logical way without gaps or missing areas of coverage. Other benefits include:
● A huge field-of-view, hence total coverage with no blind spots
● Unbroken surveillance on a single camera; no camera switching required
● Massively reduced camera counts when covering large areas
● PTZ or ePTZ around the scene during playback
However, fisheye cameras are not a cure-all for replacing fixed or PTZ cameras in every scenario, as the loss of detail plus pixel density drops are still their Achilles' heel. “Depending on camera mounting height and distance from the subject, what the user may not get from the 360 camera could be facial-recognition shots or car license plates,” said David Myers, CTO at AMG Systems. “In these cases, the use of an additional fixed camera may be required, usually at an entrance or exit.”
As fisheye cameras change the perspectives of security personnel who actually “see” the video, installers should pay closer attention when deploying them. First, installers must be conscious of where the camera is being mounted on and of the type of material of the wall or ceiling. As certain fisheye cameras are designed to blend into the decor and need to be mounted on harder ceiling material like drywall or sheetrock, plenum space where air circulation is used might not be a good option. “Aesthetics plays an important role in many installations, especially when mounted at eye level or just above eye level in a wall,” said Greg Alcorn, Global Sales Director for Oncam Grandeye.
Since a fisheye camera covers a wide area in all directions, “ceiling or mounting height is important, and cameras should be positioned strategically to provide the best coverage of the area,” Myers said. Additionally, how the camera is going to be powered (with PoE) and how it would connect to the management network should be given some thought.
Claire Huang, Product Marketing Specialist at Dynacolor, agreed. “Due to resolution drops around the edges, users should make areas of interest the center of the image. Thus, the height and location should be carefully considered.”
Another consideration is light variations in a given scene. “Very bright lights often blow out a scene or create lots of shadows, and many 360-degree cameras cannot pick up information because the image is either too dark or too bright,” Alcorn said. The brightest and darkest areas will be a challenge for the camera to resolve. “Installers should consider the entire scene when placing a camera — how much light will be visible and what in your scene is important to see for total situational awareness.”
When installed under a bright environment with lamps of low frequencies, there might be flickering as well, Huang added.
Security professionals should understand that fisheye cameras are designed to add value, rather than perform as a Swiss-army-knife solution for surveillance. Fixed or PTZ cameras might still be required to ensure fisheye cameras provide a complete overview of the scene and a conclusive evidence trail for devising proper business or security measures.
For more coverage on security products, please check out asmag.com.