One the more significant challenges facing those involved with the creation of video surveillance systems is capturing video of evidential quality in low light applications. For many years this seemingly simple task has been a bugbear for many installers and integrators. Manufacturers have tasked their R&D teams to come up with ever more innovative solutions to the problem of getting a sufficient level of light to fall onto the image sensor. In reality, for many years there has been a solution that is both reliable and efficient. With changes in manufacturing processes a good few years ago, this solution is also cost-effective. Adding light is always the preferred option in such applications. Here Benchmark looks at infrared options for surveillance illumination.
Low light conditions are an age-old problem for video surveillance systems. In recent times a number of manufacturers have introduced processing options designed to enhance camera performance in low light conditions. These work with varying degrees of success, but due to the fact they employ camera processing, there is often a trade-off in terms of performance.
With recent increases in chipset capacity, the quality of processing has increased in the past 12 months. Even before the boost in processing performance, there were a number of options designed to allow video capture in lower light levels. However, many of these had a negative impact on the captured footage.
For example, the use of slower shutter speeds allowed more light to fall onto the sensor, but the cost of this was that often real-time video could not be captured, and scenes with a lot of movement often resulted in a high degree of blur.
In Benchmark tests using technologies such as slow shutter or frame integration, we have managed to achieve fairly respectable still images in very low light conditions. What was bad news for those seeking to use the technology in security applications was that if someone ran through the scene, and operator could not discern anything about the target. In some cases it was difficult to tell if the blur had been caused by human and on a few occasions it was difficult to detect the blur against the background of noise, so motion was simply not visible.
Whilst using advanced processing options coupled with aspherical lenses can improve low light performance by a certain degree, the best solution when faced with poor lighting is without question to add light.
Conditions at the site and user requirements will dictate whether that needs to be infrared illumination or white light. It matters not; what is important is that light is added!
Recently in Benchmark, we assessed a number of the choices available to those looking to capture video around the clock. Whilst there are a plethora of options which can have some impact on the final image, nothing comes close in terms of the price/performance ratio than dedicated standalone illuminators. (This article can be read here.)
In this test of infrared illuminators, we looked at two scenarios. The first considered the performance of illuminators coupled with a camera viewing an angle of 60 degrees at a range of 50 metres, while the second looked at a viewing angle of 30 degrees with a distance of 100 metres.
Interestingly, only one manufacturer supplied two infrared lamps for this test. The other participants supplied a single lamp with interchangeable diffusers.
In the past the team at Benchmark has debated who exactly gets the benefits of illuminators with interchangeable diffusers, and this test reignited the argument. When specifying an illuminator, devices are generally selected for each individual location. The specification will be dependent upon the camera’s field of view.
In the vast majority of applications, once a camera and illuminator combination has been installed, it is highly unlikely that the devices will be moved or the field of view significantly changed.
For the installer or integrator, interchangeable diffusers do make sense if they are carrying a spare illuminator in case of failures. Unless the end-user suddenly faces a very different requirement from the system, they too are unlikely to benefit from interchangeable diffusers. It does seem to be a benefit for manufacturers only!
Functions which do add value include power adjustments and telemetry connections that do not rely upon costly proprietary plugs.
GJD Security Clarius Plus IM-8
The Clarius Plus IM-8 from GJD Security is an infrared illuminator which delivers 850 nanometre light (semi-covert). The device has a range of distance and angle specifications, all of which are covered as the illuminator is provided with an interchangeable lens diffuser pack.
The angle and range options are: 10 degrees/200 metres; 20 degrees/137 metres; 30 degrees/100 metres; 60 degrees/64 metres; 80 degrees/46 metres; 95 degrees/32 metres. The 30 degree diffuser is fitted as standard and the 10 degree pattern does not require a diffuser.
The illuminator uses high-efficiency dual core LEDs and has a power consumption figure of 26W. Input voltage can be 12V DC or 24V AC.
The illuminator power for the lighting intensity can be adjusted from 10 to 100 per cent. The device also features an integral photocell which can be adjusted from 20 to 70 lux.
The unit is fitted with a three metre fly lead which handles power, photocell following contact and remote telemetry. One note about the photocell is that it is located on the top of the main body of the illuminator. All too often, illuminator manufacturers place photocells on the rear of the devices, and while this is not an issue in a number of applications, if the illuminator is located under an eave it can significantly affect the unit’s switching.
The illuminator is supplied with a single page A4 instruction sheet and the diffuser kit. A mounting bracket is included and requires fitting. The bracket is manufactured from powder coated stainless steel, the body of the illuminator is an aluminium extrusion, and the cover is polycarbonate. The latter features a self-cleaning coating.
Installation of the unit is very straightforward. With the bracket mounted and the unit in place, the only connections are for power and, if required, telemetry and remote switching.
There are two accessible potentiometers on the side of the illuminator: one adjusts the photocell switching level and the other the power output. Aside from that, the only task is to install the correct diffuser for the required angle and range.
The process for this task requires a small flat bladed screwdriver. The installer or integrator simply prises up the bottom of the illuminator cover. You will hear a slight click as the retaining ring inside the unit pops free. The process is then repeated at the other end of the unit and the cover can be removed.
One word of warning is that if you’re trying to change the diffuser with the IR lamp in situ, there is no retainer and you’re more likely than not to drop the cover. The diffuser itself is held in place by two spots of adhesive. These are more tacky than sticky, and we lost a diffuser because it blew away when changing it in situ.
In reality, installers and integrators are unlikely to be regularly changing diffusers but even so this could be improved. With the appropriate diffuser fitted, the cover is put back into position and snapped into place.
The process is relatively simple, but dependent upon the mounting location it’s not the easiest task once the illuminator has been installed.
With the illuminator in action using the 30 degree diffuser over a range of 100 metres, light coverage is fairly consistent within the viewed scene. The foreground, within the initial 50 to 60 metres, is marginally brighter than areas between 60 and 100 metres. However, targets within the latter area are easily identified. That said, our test does indicate that the stated range should not be exceeded.
Light coverage was good up to the very edges of the viewed scene and well within specification. The test camera featured a number of low light processing options. With these deployed there was hardly any detail in the scene, and the video was less than usable. Bit rate for very low quality images was 45Mbps. With the illuminator deployed, the image not only had detail and a good degree of clarity, but bit rate also fell by approximately 33 per cent.
Swapping to the 60 degree diffuser over a range of 50 metres, light consistency remained good and with regard to the range, coverage was good for 60 to 70 metres. This meant a good level of illumination within the test area of 50 metres. The bit rate saving was also consistent at the lower range.
Across both ranges there were no hotspots or dark areas, even with high levels of motion in the scene.
Iluminar’s IR623 range is made up of infrared illuminators which deliver 850 nanometre light (semi-covert). The illuminators have specific coverage angles and ranges, and to meet the needs of the test the manufacturer supplied two models.
The A30 model has a field of view of 30 degrees and a range of 100 metres. The A60 model has a field of view of 60 degrees and a maximum range of 75 metres. Aside from these specifications, the illuminators are the same.
The illuminators make use of energy efficient infrared LEDs and feature thermal management and electronic control circuitry. Quoted life expectancy is 50,000 hours (minimum). Input voltage can be 12V DC or 24V AC and consumption for the IR623 models is 36W.
The illuminator power can be adjusted with five setting levels at 20, 40, 60, 80 and 100 per cent. There is also a timer option which works in conjunction with telemetry input. The timer can be set for 1, 3, 10 or 30 minutes. Photocell adjustments have four levels: low, medium, high and maximum. The high-sensitivity level is the only one that Iluminar gives figures for: these are quoted as 30 lux on and 70 lux off. The only other guidance is that the low setting comes on when it is ‘most dark’ while the maximum setting has the illuminator operative ‘for the longest period’. Finally there is an option to disable the day/night sensor.
The camera is fitted with a three metre fly lead. Connections are for power input, telemetry and a relay.
When you take a closer look at the Iluminar models, one thing that you’ll notice is the lack of any potentiometers. All necessary adjustments are made via a remote control which is supplied separately. There is no option to manually control the settings.
There is an issue here, in that installers and integrators have to purchase an additional device in order to use the basic core functions. The product’s specification sheet does mention that certain functions are controlled via a remote, but does not state this is a required accessory that must be separately purchased.
Manufacturers who offer remote controls as an extra but do not provide manual adjustments must realise that installers and integrators will not be happy about purchasing controllers because the manufacturer has saved themselves money by not fitting potentiometers.
The illuminators are supplied with a 12 page A5 user guide. There is also a powder coated stainless steel bracket with fixings. The unit itself is made from extruded aluminium and the lens cover is rigid polycarbonate.
Installation is a simple task and merely requires the supplied bracket to be attached and the unit mounted. With the connections for power input, telemetry and relay (if the latter two functions are required) made, then alignment and configuration can begin.
The remote control device makes use of icons which make its use relatively simple. The control buttons are arranged in three rows: timer, photocell and power. There are also three control buttons: disable remote, a button to flash the LED on the illuminator which is receiving a signal from the remote and reset.
If you have multiple illuminators in one location, such as where bracketry on the corner of a building supports a couple of cameras and associated lamps, we found that it was not possible to consistently work with only one illuminator using the remote.
There is a workaround. Once the settings for an illuminator have been ‘locked in’, the device will not communicate with the remote again until the power has been cycled. Therefore, where illuminators are in close proximity, you need to lock the settings on both devices, cycle the power on one, set that specific unit up, lock in the new settings, recycle the power on the second unit and repeat the process. It’s clumsy.
Using the A30 variant for the target range of 100 metres, there was a decent degree of consistency within the field of view, and whilst targets could be identified throughout the full range, detail did drop-off a little in the last 20 metres.
Coverage was generally good with no discernible fading or hotspots, even with high levels of motion in the foreground.
As stated earlier, when using on-board processing the camera required 45Mbps to deliver what was frankly a poor quality image. Using the Iluminar device, not only was the quality significantly improved but the bit rate fell by approximately 38 per cent.
Switching to the A60 model to view the 60 degree scene over 50 metres, the illuminator was more consistent over the full range and beyond. As with the A30 model, consistency was good and the light was well-balanced with no pooling.
We did note that during periods of dawn and dusk, the illuminator would occasionally cycle on and off. Given that the manufacturer uses differing on and off light levels, this does indicate that the photocell control software may need a slight tweak.
The VAR2-IPPOE-i6-1 from Raytec is an 850 nanometre (semi-covert) infrared illuminator which uses IP connectivity and PoE+ for power input. The illuminator makes use of interchangeable diffusers. It is supplied as standard with a 35 x 10 degree diffuser fitted, and a 60 x 25 degree diffuser included with the unit. The illuminator can also be used without the diffuser which gives a 10 degree angle and a maximum range of 200 metres. With the 35 degree diffuser fitted the maximum range is 120 metres, falling to 70 metres with the 60 degree diffuser. Additional 80 degree and 120 degree diffusers are also available as optional extras.
The illuminator makes use of high-efficiency LEDs and integral thermal management system to enhance reliability. It also includes hotspot reduction technology which the manufacturer claims delivers light where it is needed due to an elliptical beam shape; this reduces light spillage.
The hotspot reduction technology also eliminates issues with overexposure on objects close to the device.
Configurable elements of the illuminator include adjustable power output (20 to 100 per cent), adjustable photocell trigger point, power boost to increase output to 120 per cent for a duration of 10 seconds, a timer and a deterrent feature with selectable patterns. The latter feature is not really worthwhile on an infrared unit.
The illuminator makes use of PoE+ power input; a traditional 24V AC power input can also be used. The unit is fitted with two 2.5 metre fly leads. One of these is pre-terminated with an RJ 45 plug for network and PoE connection. The second is for connection to a standard PSU along with an external input and output.
The interchangeable diffusers are accessed via a panel on the bottom of the illuminator. It is held in place by two hex head screws; with these removed the cover is pulled free and the diffuser slides out. Replacing it in situ is relatively straightforward. The photocell is on the back of the illuminator and as such care should be taken if installed under an eave.
Device configurations are carried out using the illuminator’s integral web page. A supplied USB stick contains a device discovery utility, a user guide for the utility and the full installation and setup manual.
Discovery utilities are very common in video surveillance, and generally these will run off a CD without any need for installation. However, the Raytec variant not only requires installation but also needs the .NET framework to run. The installation package does not include this, so the server needs to be on-line. It’s one area where Raytec might learn a lesson from its camera partners.
We did spot one anomaly with the discovery tool. If the illuminator is on the same subnet as the server, the tool would not find it! However, using a browser we could log into the device.
The GUI is relatively clean. At first glance it does seem as if there are a lot of options, but many of the screens could be combined. The Home screen is an illuminator control screen, with adjustments for power, boost and deterrent. The latter, as already mentioned, is superfluous on an infrared unit. It flashes the light to deter intruders, so has more credibility with white light.
The Settings/Groups menu contains many of the settings from the Home screen, plus a couple of additions. There is then an Advanced Settings screen which includes an override duration plus details of external inputs and outputs, along with photocell sensitivity. The Access screen sets login credentials, and the Network screen covers the IP parameters. There is then a page of basic information including restore and reboot functions, followed by two pages of diagnostics. Finally, there is a page dedicated to firmware upgrades.
In the field, with the illuminator set for 35 degrees coverage and 120 metres range, like coverage throughout the viewed scene was good and consistent. Due to the viewed area being less than the total range, there were no issues of light fade in distant parts of the protected area. Hotspots or faded areas were not an issue, even with high levels of footfall in areas close to the illuminator.
Because of the nature of the test, the diffuser was changed with the lamp in situ. Because of the mechanism Raytec uses, this was not a significant issue. Whilst we don’t expect many installers are integrators to change diffusers in the field, the process isn’t painful if such a task is necessary.
Similarly, with this 60 degree diffuser deployed over a range of 50 metres, the additional range of the product (70 metres) meant that light was consistent throughout the full field-of-view. As with the other illuminators, the Raytec unit saw a reduction in bit rate plus a significant increase in quality over the test camera’s integral processing functionality. Bit rate fell by 32 per cent.
During periods of dawn and dusk, the illuminator performed as expected with regard to photocell switching.
This test included devices from the main three suppliers of infrared illumination. Our conclusion is that you pay your money and you take your choice. Performance between all three was very similar, build quality offered no concerns, and the real differentiators came down to additional features and functions.
One member of the test team raised an interesting point. He currently has sites operating with illuminators from all three manufacturers which are three or four years old. None have the additional features such as remote controls, interchangeable diffusers, nor many of the proprietary technologies that ‘enhance’ basic performance. In his opinion, the performance is no worse than that offered by the latest breed of devices.
To installers and integrators, what matters most is consistent illumination, and all devices tested can offer this.
GJD Security Clarius Plus IM-8
The Clarius Plus IM-8 from GJD Security performed well, and showed consistent illumination in both parts of the test. Because we had to change the diffuser mid-test, we discovered the downside of the mounting system employed by GJD when a lens blew away; never a good thing in the dark.
Range was as specified, but should not be exceeded at longer distances. Performance was consistent in changing conditions. While the illuminator is recommended, it would certainly be more highly considered if GJD changed the diffuser mounting system to something more reliable.
Iluminar’s IR623 illuminators are similar in performance to the other units with regards to light consistency, and also carry the same provisos with regards to range. We did spot an anomaly with the photocell performance, in that at certain light levels both showed odd cycling patterns.
This is a slight issue and can be easily rectified. There is also the fact that there is no alternative for installers and integrators but to buy an additional controller to access the most basic functions of the illuminator. Despite this, it is on a par with the other units. The illuminators are recommended but would be better if a free control option was available.
The VAR2-IPPOE-i6-1 gave consistent light performance, both in terms of range and coverage, and was again similar in performance to the other units. Where this model differs is that it supports IP-based connectivity and uses a GUI for configuration.
The test team felt that the interface could certainly be improved. Raytec could learn from the surveillance camera sector which has pretty much delivered intuitive and simple GUIs and utilities for many years now.
The VAR2-IPPOE-i6-1 is recommended, but could be improved with a better discovery utility.