COMBINING all the developments of the past 4 years into one package, the new Spectra IV represents a features and cost package that looks very hard to beat. Like the Spectra III before it, the Pelco Spectra IV is described by the manufacturer as a dome system and there’s a good reason forthis. The Spectra IV is modular, with each of its primary componentsinterchangeable. The idea behind this is that cameras can be upgraded, replaced or removed for maintenance with no disruption to vital coverage. In terms of core features, Spectra has a 35x optical zoomand 12x optical, 540 lines horizontal resolution, strong 128x wide dynamicrange, motion detection and electronic image stabilisation. There’s also windowblanking, camera title overlay, password protection, preset freeze frames,integrated passive UTP circuit, internal clock and built-in surge and lightningprotection. There are other manufacturers out there whose promotional guff talks up massive optical and digital zoom range combinations but in truth the relationship between F-stop and zoom lens means full extension of a zoom lens will shoot the hell out of claimed minimum scene illumination outside ofdaylight hours. Add a digital zoom to the equation and things start to fall aparteven in reasonable conditions. At 35x optical, Pelco’s new Spectra is right on the money when it comes to balancing usability and cost effectiveness. As Spectra’s always have been, this camera is very far-sighted indeed. Along with strong zoom capabilities, Spectra IV has on-screen compass, tilt and zoom display, 400 degrees per second panning and 200 degrees per second tilt speed (there’s also 0.1 degrees per second creep), 7 alarm inputs, action on alarm and resume after alarm, user-defined tour patterns, auto-flip and programmable zoom speeds. ModularitySpectra IV comprises 3 components – a back box, a dome drive and a lower dome unit. These are 3 components that are interchangeable with any other Spectra IV dome system and we’re going start by talking aboutthe back box. It’s right about now that your Spectra IV morphs into half adozen potential cameras – what sort of dome camera that is really depends onyou. Back box options include environmental (external) in-ceiling, internal in-ceiling, indoor surface mount, standard and environmental pendants, heavy duty, pressurized and stainless steel. That pressurized environmental unit, which is IP66 rated for challenging maritime climates, has a positive atmosphere inside that completely excludes moist air during manufacture and virtually guarantees you’ll have no corrosion as long as the dome seals aren’t compromised. Vital to the idea of modularity is the ability of aninstallation to recall the presets an installer painstakingly loaded into itduring commissioning. The beauty of Spectra IV is that if you change a domedrive there’s no need to reprogram presets or tour details – that’s all in theback box memory, along with labels, patterns and zones. Meanwhile that UTP circuit mentioned earlier allows easyuse of unshielded twisted pair comms options from manufacturers like NVT. UTPcomms in video surveillance installations have a bunch of benefits – longerrange either before or after signal amplification is a key strength – as isresistance to the effects of EMI or RFI in shared cable troughs or buildingrisers. There are some installations that are born to hate coaxial cable andit’s nice to know the Spectra IV is optioned to make life easier should you befaced with the prospect of hauling cables over hill and dale to avoid a plantroom or power supply. Dome drivesThere are 2 key dome drive options – a 35x day/nightmodule and a 23x day/night module. Both these optical units employ a ¼-inchEXview HAD CCD. Of the two, the 35x unit has stronger specs at 540 lineshorizontal, while the 23x unit has 470 lines of resolution. Signal-to-noiseratios are identical at 50dB, while the all important wide dynamic rangenumbers are 128x for the 35x camera and 80x for the 23x camera. In terms of minimum scene illumination, Spectra IV’snumbers are quoted against an ambient scene illumination of 35IRE – that means there’s some infrared light present even though that quoted figure of 0.00014 lux minimum scene illumination for monochrome (at 1/1.5 second) might make you think the 35x day/night camera version can see in complete darkness.Taking the 35IRE into account, Spectra IV gives a picturein 0.50 lux at 1/50 sec in colour, while black and white performance is, asmentioned, way down at 0.000014. If you choose the 23x day/night camera you’ll get a colour image at 0.08 lux and a monochrome image at 0.013 lux. Supporting minimum scene illumination is a Pelco feature called LowLight that allows cameras to compensate for scenes where there’s very little scene illumination. The 35x dome drive also features electronic imagestabilization that digitally reduces blurring of the camera image caused byvibration caused by wind or traffic movement – especially when pole mounted. In the case of the 23x dome camera you get built-in motion detection. Along with these dome drive cameras there’s a pair ofstandard cameras, one colour and one black and white, each with a 22x timeslens and an EXview HAD imager for improved sensitivity. Pelco says it put special effort into the design of thedome bubble and the camera lens – the idea being to ensure “optimal opticalrelationship between the lens and the bubble”. The result, Pelco says, iscrystal clear video at long focal lengths. An important element of the Spectra IV is a series of software protected software enhancements designed to increase performance and make operation easier. There’s an internal scheduling clock that allows presets to be scheduled, while window blanking lets administrators program up to eight 4-sided, user-defined privacy areas. The camera’s on-screen compass and tiltdisplay are designed to make for easier preset programming. Pelco Spectra IV represents proven technology at anextremely good price. Modern speed dome cameras like this one are reaching such pinnacles of sophistication it’s tough to see where manufacturers will takethem next.