The bench test 1: Removing the mystery

What our experts say …
To date, network cameras have occupied a small niche in the mainstream CCTV market. But with the arrival of models such as Sony's SNC-RZ30, there is a strong incentive to reassess their role, both in remote monitoring and as a viable and effective alternative to conventional surveillance cameras. The RZ30 overcomes many of the real and perceived limitations of network camera operation by being simple to install and configure and exceptionally easy to use.

Typically for a Sony product, it is a compact and stylish design with the camera module housed in a curvy cylindrical enclosure mounted on a pan-tilt mechanism. On the rear of the base unit there is a standard Ethernet connector socket; a BNC socket carrying an analogue PAL video output for connection to a monitor; a plug-in terminal block for communications data, alarm inputs and outputs; and a socket for the 12 volt DC supply from an external mains adaptor module.

Around the front are two PC card slots for optional memory stick adaptors; the memory cards are used to store single or sequenced still images, either manually or when an alarm is triggered. However, as we'll discover in a moment, these slots may have a much more interesting application. The camera is based around a 1/6th inch interline 800,000 pixel CCD with a minimum illumination of 3 lux. The lens has a 25x optical zoom and this can be electronically extended to 300x. All exposure and white balance systems are fully automatic with manual overrides for shutter or aperture priority, backlight compensation, gain (-3dB to 28dB) and shutter speed (1 to 1/10,000th sec).

White balance can be set for indoor, outdoor and auto-tracing and there are user/operator adjustments for saturation, sharpness and contrast. Additionally it has a day/night function with automatic switching to monochrome opera-tion and an electronic stabiliser to reduce or elimin-ate the effects of camera shake. The pan/tilt mech-anism provides 340 degrees of rotation – end to end in two seconds – and it tilts though 115 degrees in just 1.5 seconds, so it is surprisingly agile.

Build quality is up to Sony's usual high standards. There are two busy-looking PCBs in the base for the communications, camera control and PTZ electronics. These are securely bolted to a tough-looking cast alloy chassis. The pan and tilt mechanisms are unusual in that they use a form of direct drive motor, which provides little torque but gives exceptionally precise control; the lack of belts and gears also makes them fast, responsive and almost completely silent.

Most of the camera electronics are mounted inside the module on a cast alloy sub-frame but, despite its bulk, it is light and finely balanced. The camera can be suspended from a quick-fit ceiling mount or configured for table-top operation; an option in the set-up menu allows the image to be inverted. (When the camera is in table-top mode still image capture is upside down, which can be a little disconcerting.)

The network side of things centres on the camera being connected by a standard 'crossed' Ethernet cable to a suitable PC or a network. If the network is also connected to the Internet it is possible to view images and control the camera from anywhere in the world. The RZ30 has its own IP address and effectively operates as a video server, with the image and control facilities accessible from any network-enabled PC via standard web browser software such as Microsoft Internet Explorer. A useful spin-off from the network/Internet connection is the RZ30's facility to send still images by e-mail to a nominated address when an alarm is triggered.

To view a live video image and control the camera, its unique IP is entered into the browser's address field and a 'Welcome' page is displayed. Providing the user has right of access and doesn't require a password, the operator then selects either an Active X or Java Applet 'viewer' and the image from the camera appears on the screen. Up to 50 people can access the image at any one time.

A toolbar along the top of the page has icons to display a set of controls for the PTZ functions, still image capture, options for sending images by email or file transfer protocol (FTP) and alarm settings, and a password-protected configuration menu. On the set-up menu there are settings for time, date and camera ident displays, detailed camera adjustments, security functions, alarm sensors, activity detection, network configuration, preset positions (up to 16), tours (five programs), alarm outputs, scheduling and a variety of housekeeping functions.

While testing the RZ30 we discovered a couple of additional functions not mentioned in the instruction manual or documentation. The first is mouse-controlled PTZ; the operator simply defines an area of interest in the image using the mouse and the camera automatically realigns and zooms in on it. The second facility is wireless networking. Cameras with the latest firmware support a Cisco Aero wireless card, which does away with the need for a network cable.

Unfortunately wireless networking appears to be a work in progress and at the time of going to press details were still somewhat sketchy so we were not able to evaluate it fully. Unanswered questions include whether it can be used with industry standard 'Wi-Fi' cards and protocols but assuming that it does, or can be upgraded to do so, it promises to make installation even easier and allow it to be used in areas where cabled network coverage is difficult or non-existent.

The initial set-up should only take a few minutes and first job is to assign the camera an IP address. There are two methods; the easiest is to let a utility program on the supplied set-up disk do all the hard work. This is Windows only (9x, 2k/XP), which will doubtless annoy Mac users but it is very straightforward and worked first time using the default settings.

Alternatively the IP address can be assigned using Address Resolution Protocol (ARP) commands from within a DOS window but this is a cumbersome procedure and only likely to be needed in special circumstances or where there are problems using the Windows set-up program.

There are some operational quirks when it comes to PTZ control and image refresh rates. Of the two 'viewer' options for this model the Active X applet is noticeably better with smoother movement and faster, more responsive controls. The Java method is slow and jerky and prone to freezing. With both types of viewer there is a delay between a command being given and it being acted upon.

The Active X viewer suffers least in this respect and it varies from a fraction of a second, hardly noticeable, to a second or more, largely due to network constraints including speed, bandwidth and how busy it is.

This is also a factor in how frequently images are updated, which can be from one frame a second to 30 fps, though the specification of the viewer PC and other software, such as virus scanners, can also have an impact on refresh rate. Together a long time delay and slow refresh rate can make it difficult or even impossible to track movement and activity using the normal PTZ controls. While this is a common problem with network cameras, the RZ30 does have the mouse/on-screen controlled PTZ function and this is a major advantage when it comes to navigating around the area of view.

Another welcome feature is zoom-controlled pan/tilt speed. This makes it easier to make fine adjustments to the camera's position. The degree of adjustment on the RZ30 would put some hard-wired PTZ systems to shame and this is possibly due to the use of direct drive motors, rather than the more common stepper type motors, which have a finite resolution. This shows up most clearly at extreme magnification where it is possible to move the camera by increments of a fraction of a degree (around 1/3 degree per step), movements so small that the camera hardly appears to move.

  Three resolution settings are available; at the largest/highest setting (640 x 480) image quality is excellent and apart from the differences in presentation and the fact that the picture is displayed on a PC monitor, there is little to distinguish the quality of a static image coming from the RZ30 and that of a conventional analogue CCTV camera.

In good light the image always contains a lot of fine detail although at magnification settings over 25x, when the electronic zoom kicks in, resolution falls off quite quickly and at the highest levels the image becomes quite noisy and heavily pixellated so it is only possible to make out coarse details. The effects of compression and slower refresh rates show up when the image contains a lot of movement but it is not intrusive and offset to some extent by very low levels of picture noise.

Thanks to digital processing and the Internet that means that the image looks crisp and clean whether it's coming from a camera a few metres away or from the other side of the world. The RZ30's auto exposure systems react quickly to changes in lighting.

What the manufacturer says ...
The Sony SNC-RZ30P network camera was introduced to show our commitment to the developing of a range of innovative e-surveillance solutions. The camera incorporates a built-in Internet Protocol server as well as integrated pan-tilt-zoom capability.

Equally suitable for surveillance and remote monitoring, the SNC-RZ30P video network PTZ camera is ideal for any environment that requires high-quality colour video to be sent over the network with the flexibility of remote operation, all in an attractive and unobtrusive package.

The SNC-RZ30P appeals to a wide range of users seeking the convenience of an "all-in-one" camera with remote PTZ control, capable of direct connection to any Local Area Network (LAN).

It is the first IP camera that can stream up full motion video (25 frames per second) of high quality colour images at VGA (640 x 480) resolution. Pictures from the SNC-RZ30P can be viewed via a standard web browser or suitable application software running on a PC connected to the network.

The direct drive pan-tilt mechanism is virtually noiseless in operation; a key benefit for applications where it is vital not to disturb the environment with intrusive noise. The Auto Focus lens offers a large 25x optical zoom ratio to resolve fine detail, even during night time, due to the Day/Night function.

The SNC-RZ30P supports both ceiling surface as well as desk-top mount, while the image stabiliser ensures a steady shot at all times. Integration into existing video surveillance systems is possible, due to the composite video output that comes as standard.

Other features include alarm/event handling via either the camera's embedded motion detector or sensor input and 16 programmable pre-set positions. For even greater flexibility, the SNC-RZ30P is additionally equipped with a PCMCIA type II slot (x2), for example to extend its local image memory by adding an optional PC card with memory stick. A transparent RS-485/232C serial interface is also provided for control of other peripheral devices.

Reader Service No 100