Bench Test 1: Small but powerful

What our experts say…

If there is a limit on how small PTZ dome cameras can get, then it is clear that there is still a very long way to go, if the JVC TK-C625 is anything to go by. Whilst this is one of the smallest full-spec dome cameras on the market, the mechanical and electronic bits and pieces inside the slim case are by no means overcrowded, and that is in spite of a formidable list of features.

It begins with the camera module, which is based on a 1/4-inch interline transfer CCD mounted behind a 12x (3.8 mm to 45.6 mm) optical zoom lens. The image sensor has 480k effective pixels yielding an impressive resolution figure of 540 lines. It's a full-range day/night design – JVC call it 'Super LoLux' – with an IR cut filter that flips across the face of the sensor to give a low light sensitivity (in black and white mode) of only 0.075 lux.

In colour mode with all of the low-light enhancements enabled sensitivity is down to just 1.8lux. Focus is fully automatic with manual and one-push overrides; the exposure options include manual and automatic shutter, AGC and white balance.

It is designed to be partnered with the JVC controllers (RM-P2580, GSC-200J/VR etc) but as it uses standard communication protocols (RS-422A/RS-485 interface) it can be integrated with a wide range of control systems, including PC-based set-ups using software downloadable from the JVC website.

The camera is mounted on an impressively agile (360 degree endless rotation) pan/tilt platform with a full 180-degree tilt and auto-flip feature, to track objects and subjects as they pass beneath the lens. For the record pan/tilt speed is variable and in preset mode it spins at between 1.5 to 180 deg/sec and the tilt action flips the camera at 1 to 120 deg/sec.

The C625 can store up to 100 preset positions, each with its own set of programmable exposure options. It has an Auto Pan and Patrol functions the latter with up to user-set three patterns based on stored preset positions. Patrols can be sequenced at preset intervals of 1 to 60 minutes. The Auto Trace function stores a 30-second sequence of manual camera movements and this can be set to repeat at 30-second intervals.

Pan and tilt limits may be set manually and up to eight privacy masks can be programmed with up to four of them on the screen at any one time. The dome has an extensive set of on-screen displays and in addition to camera title or ID it can be set to show its position in relation to 16 titled areas or by compass direction (in eight divisions).

A single alarm input and output is provided. When activated it can be set to steer the camera to the Home position or any one of the 100 presets. The alarm output can be configured to trigger when the camera switches from day to night (or night to day) mode, moves to a preset position or receives an alarm input.

Externally there's not a lot to see, the camera and PTZ mechanism is housed inside a cream coloured plastic cylinder with a diameter of just 120mm. The slim profile makes it look quite long, measuring 200mm from the tip of the transparent dome to the base (top) of the housing. It's a distinctive shape, possibly even a little odd when the entire length of the body is left exposed is suspended from a pendant mount but the small size and relatively low weight (it tips the scales at just 1.3kg) means there are plenty of installation options, should it be necessary to reduce its profile or visual impact.

The housing is divided into three distinct sections. All of the external connections are routed to a multi-way connector on the base that plugs into a mounting plate with a bayonet type locking mechanism and coiled safety suspension cable. The power, video and comms feeds are routed through a set of screw terminals and quick-fit plugs so in most cases installation and wiring should be a relatively swift and straightforward exercise.

The lower third of the case houses the power supply components (it requires a 24 volt AC feed) and the rotary transformer. This section of the case is ventilated by a tiny cooling fan set into one of the circular metal chassis plates in the camera's centre section. This part also houses one of two large PCBs; the upper one handles video processing, communications and PTZ functions. The lower one, mounted below the fan and fixed to the rotating pan/tilt platform, is responsible for motor control. Two small stepper motors move the camera module using surprisingly sophisticated twin-belt drive mechanisms and undoubtedly contribute to its impressive smoothness and accuracy.

Inside the clear polycarbonate dome – more on that in a moment – the black cased camera module sits behind a black aluminium shroud. The camera is mounted on a simple pivot arrangement between a pair of metal arms fixed to the chassis. The whole assembly feels very rigid and looks superbly well built. In contrast to most of the dome cameras we have looked at recently the transparent dome on this one looks and feels unsubstantial but our biggest concern is the ease with which it can be removed. It is a simple screw fit and couple of twists is all that it takes, exposing the camera and PTZ assembly and making it vulnerable to interference, damage and ingress of dust and dirt.

Setup and operation

JVC's considerable experience shows through with the TK-C625 dome

All of the dome's primary functions are controlled through a set of menu-driven on screen displays. The first Setup screen appears after the Menu button on the system controller has been pressed and held for longer than a second. This shows three options for Position Setup, Cameras Setup and Control Unit configuration. Each menu leads to a series of sub menus with most key settings on the Camera Setup menu group.

There are seven options covering setting the Privacy Masks, composing Camera ID, Area and Position titles, alarm setup, exposure and video controls, selecting and enabling Auto Pan, Patrol and Auto Trace modes, and setting preset Positions. Additionally, each preset position has its own camera setup screen and this covers iris mode, backlight control and white balance with preset level controls for fine-tuning red and blue gain.

Performance

JVC's considerable experience in the design and manufacture of video cameras is clear to see on the C625 and overall image quality is excellent. In good natural light it rivals the best static day/night cameras with resolution at or very close to the manufacturer's claimed figure.

We suspect that the auto exposure systems can be left safely in charge in most installations; they are smooth and responsive and the only time there's any indication that they are doing their stuff is during a fast pan when the brightness levels pulsate slightly as the scene lighting levels change.

Colour accuracy and balance across a range of lighting conditions is very good and manual intervention should only be required in difficult mixed and tube lighting conditions. The switch from colour to monochrome operation is smooth and fast with only a small change in image brightness before and after the changeover point.

Picture noise levels are very low; as light levels fall there is a steady increase in grain but it remains well controlled and largely insignificant up to and beyond the day/night switching point.

The Pan/Tilt platform is fast with negligible overshoot and the high-ratio gearing means movement is smooth and positioning accurate.

What the manufacturer says ...

The TK-C625E from JVC is a slim and discreet dome camera that is ideal for most applications. Installers will find it easy to use as it requires simple installation and little maintenance. It is slimmer than conventional dome cameras (120mm x 190mm) and comes with a complete set of operational features using the very best in CCTV technology developed by JVC. It comes at an exceptionally competitive price and is ideal for all markets.

The TK-C625E dome camera has powerful 540 lines of horizontal resolution for sharp and high resolution images. The camera promises excellent images with a 12x optical zoom and 360 degrees endless panning 1/4-inch CCD for superior image processing. The Super LoLux sensitivity enables optimum performance in low light levels such as dark winter nights or inside environments. The camera also comes with a day/night surveillance with IR cut filter.

Enabling installers to configure the camera for a wide variety of applications, the camera comes with a user selectable built-in menu 100 preset functions for added flexibility and privacy masking feature. It also has auto return, auto patrol and auto trace functions.

JVC's comprehensive range of brackets and outdoor housings are available. The camera looks very slick within the JVC recessed ceiling mount. Because it is so unobtrusive, this camera is effective in most CCTV environments. JVC also stocks an IP network mini-sized dome camera, the VN-C625U.