New Technology Supplement

In Sharp Focus

Camera technology keeps objects in focus simultaneously

• By Raul Calderon
• Oct 01, 2006

NOT too often does the security industry see new imaging technology -- at least not one that provides system designers, installers and users with a unique feature set that delivers improved efficiency. The introduction of Sanyo's new pan-focus technology is of great significance. This technology allows video surveillance cameras to focus on every object in the camera's field of view -- no matter how close or far away from the camera. In addition to the improved identification capabilities afforded by the expanded depth of field, no manual focus adjustments are required, allowing pan focus cameras to provide an extended coverage zone even in unsupervised system applications.

The introduction of Sanyo's new pan-focus technology is of great significance. This technology allows video surveillance cameras to focus on every object in the camera's field of view -- no matter how close or far away from the camera.

Back Then
Before the development of pan-focus technology, it was generally not possible to achieve high-resolution imaging with a large depth of field for video surveillance applications. Sanyo took this challenge head-on and worked to overcome it by developing a unique lens that offers high resolution and high picture quality. This was the beginning of a beautiful product. Deep focusing techniques and digital signal processing make it possible for the camera to take the original image provided by the lens and apply sharp focus to every object in the frame.

This integration between the lens and the camera provides pan-focus cameras with 520 TV lines of resolution and extreme depth of field, allowing the cameras to stand out from the norm.

Traditional, vari-focal lenses have some well-known weaknesses. For example, with a vari-focal lens, objects in front of and behind the main focus point appear blurred. Pan focus compensates for the problem, keeping all objects in focus -- either near of far. Now, sharper images of more expansive coverage areas can be produced, avoiding the need to cross-shoot multiple cameras.

The days of manual focus adjustments are gone with pan focus technology. However, it is still possible to remotely zoom in on specific objects in the frame to capture a specific ID shot. Some units have an integrated PTZ mechanism; for other cameras, there is an optional camera control unit that operates the remote zoom feature. With all objects in focus, it becomes easier for security personnel to monitor images and identify suspicious situations. It also makes identifying individuals, vehicles and other objects within a scene easier. In addition, given its expanded coverage capabilities, one pan-focus camera can often replace multiple cameras, thus reducing initial system costs and long-term cost of ownership. While some pan-focus cameras integrate RS-232/UTP functionality, other units offer integrated IP control, as well. Both of these features are offered as retrofit options for units not initially integrated.

Benefiting All
While the benefits to the end user are clear, installers and integrators also can benefit from pan-focus technology. Since there is no need for focus adjustments, installation time is reduced. Field of view is quickly set and can easily be fine tuned to the user's preferences from the head end after the camera is installed. Lower installation cost is always an added advantage.

Every pan-focus unit offers an integrated or optional network board for use in applications where the customer is transitioning to an IP-based, networked platform. Before the development of pan-focus technology, IP-based systems had experienced image delay through the network due to focus adjustment time lag. Pan-focus technology enhances overall safety and security in real time.

Even with the increased amount of information coming from images, where every object is in focus with a larger depth of field, video signals from pan-focus cameras do not require any change to existing DVR/NVR systems and will not affect image file sizes, eliminating the need for more storage. In fact, the horizontal-resolution (520TV lines) and the frequency band of the image are the same as with earlier cameras.

One of the developments in surveillance today is the advent of video analytics. Yet typical vari-focal lenses have a shallow depth of field that doesn't allow the lenses to offer useful images outside certain areas of a scene. With its enhanced depth of field, pan-focus technology provides video analytics with a more detailed canvas area resulting in enhanced functionality.

Still Growing
The first pan-focus camera introduced was a day/night, vandal resistant dome camera. Housed in a tough, die-cast aluminum enclosure and a polycarbonate dome for extra durability, the VDC-DP7584 is IP-66 rated and has intelligent backlight compensation and a motion detection capability. It can be surface-mounted on a wall, ceiling or rooftop application. The camera also can be installed with RS-485, coaxial control and UTP transmission capabilities. Additional options include a network board.

With the benchmark performance provided by pan-focus technology, a full line of new products will be released to replace current models using vari-focal lenses. The initial introduction of pan focus included indoor mini dome, vandal resistant dome and weatherproof camera configurations. Plans for the continued rollout include pan-focus PTZ versions of the mini and vandal dome models available for conventional analog system installations, as well as systems employing UTP/RS-485 control and IP-based networked systems. Additional pan focus configurations are also in development.