What our experts say …
The last Extreme outdoor day/night camera we looked at, back in 2005, was the ZX55, a great beast of a thing, built and designed in Canada where they know a thing or two about harsh environmental conditions. It was a highly distinctive design, with an integrated IR illuminator, but what made it rather unusual was the fact that it had twin cameras, one for colour daylight operation, the other, black and white, for night mode.
It was an interesting, though on the face of it, a somewhat eccentric approach, because at the time the vast majority of day/night cameras used single image sensors. This has obvious advantages in terms of cost and design but as the Extreme camera proved, all other things being equal, in very low and zero light conditions a dedicated black and white camera can produce a clearer image than a black and white picture derived from a colour CCD.
Dual sensor models continue but Extreme is also a member of the single sensor club, and to make sure the EX30 – which we are looking at here – doesn’t get mistaken for an ordinary day/night camera with an IR illuminator, it has been designated an ‘Infrared Imager’.
As we will see Extreme has a way with words, and reading through the specs you might be persuaded that it’s much more sophisticated than it actually is. For example, the instruction booklet describes the auto iris lens as ‘Vari Focal’, which basically means it has a manual focus adjustment.
Then there’s ‘Black Diamond Technology’ and ‘High Fidelity’ infrared illumination. The website explains it thus: “…even Illumination lights the foreground and background of an entire scene, eliminating hot spots and underexposure”, and it “…enables video analytics to immediately detect a security threat”. There’s even more baffling gobbledygook but as far as we can make out it refers to a frosted window in front of the bank of IR LEDS, which diffuses the IR beam and makes it easier for operators to spot things…
Other less glamorous sounding but arguably equally important features include the 1/3-inch MX7 CCD image sensor’s vital statistics. It has 572 x 582 effective pixels array yielding a claimed resolution of 550 lines in colour mode, and 570 lines when operating in black and white. The lens is an auto-iris type, IR corrected, with a 5-50mm tele/wide adjustment.
Low light sensitivity in colour/daylight mode is 0.02 lux, and 0 lux, with the IR illuminators on and the servo-operated infrared cut filter behind the lens out of the way. The IR Illuminator is controlled by a photocell mounted next to the lens; switching threshold and LED brightness are both adjustable. Its power requirements are uncomplicated and it runs happily on a 12-24 volts AC or DC supply.
The illuminator consists of a bank of 102 850nm IR LEDs, which emit a dull, just about visible red glow; fully covert 950nm LEDs are also available as an option but these result in significantly degraded performance. Extreme’s operating distances for 850nm LEDs puts ‘detection’ at 100 metres, ‘classification’ at 90m, ‘recognition’ at 60m and ‘identification’ at 45m.
It is rugged and weatherproof, built to NEMA (National Electrical Manufacturer’s Association) level 4 standard, which is very roughly equivalent to an IP66 rating.
The case is hewn from tough alloy, with rubber gaskets sealing the front and rear covers. Power and video cables emerge through a sealed grommet in the base of the housing and pass through the mounting bracket, for added security.
Apart from the sunshield it’s a fairly featureless black box; the lens sits behind a tough polycarbonate window supported and protected by a rather ill fitting (on our sample) black foam pad. This also holds the IR illuminator’s photocell sensor in place against the front window. Above the lens is the frosted diffuser, which we take to be part or all of the Black Diamond Technology feature.
Inside the case the camera module and lens plus the PCB with all of the IR LEDs are mounted on a simple alloy chassis that slides into the housing.
The removable rear panel opens to reveal a second chassis plate supporting two small power supply PCBs, for the camera and the IR illuminator. The latter has the two preset adjustments for the IR illuminator panel.
Setup and operation
After deciding where to mount it, and what to point it at, the only other considerations when installing the EX30 are the IR illuminator’s sensitivity and brightness controls, and adjusting the focus and the tele/wide setting. The only tricky job is the last one; the lens sits well inside the case so getting at the two locking knobs requires a certain amount of dexterity, not to mention thin fingers, so forget trying to do it whilst wearing gloves. There are no other controls, adjustments or on screen displays, which makes a change, and all exposure and white balance settings are carried out automatically. The only other point worth mentioning is that the camera’s switchable IR filter function operates semi-independently of the IR illuminator, so it is possible, albeit only briefly, for the LEDs to come on whilst the camera is still in colour mode, though in normal use this unlikely to ever be a problem.
Performance
Image quality in good daylight is much as you would expect from such an uncomplicated design. The lack of extra exposure options is worth bearing in mind as the camera is unable to deal with complex lighting conditions; strong backlighting or bright lights in the scene area can cause problems, so extra care needs to be taken in its placement and aim. Nevertheless, in good daylight the image is crisp and clean, resolution is nudging the manufacturer’s figure, there’s negligible noise and colours are natural looking. Colour accuracy does waver when used in mixed or artificial light, producing a slight greenish tint under tube lighting. As light levels fall the EX30 comes into its own, and although noise levels increase they do so at a slower rate than most rival day/night cameras. When the camera switches to B/W night mode the image brightens up noticeably, and the noise drops off once again.
Eventually, as light levels fall to zero the IR illuminator switches on, and this produces an even pool of light in front of the camera. Extreme’s distance ratings strike us as a touch optimistic but it certainly provides a good field of illumination up to around 30-40 metres in front of the lens. The camera is solidly built and well supported and there were no stability problems during the shock tests, courtesy of the new and improved SI rubber mallet (the old one was looking a bit battered…).
