Dahua Integrated IR PTZ TestedBy: Ethan Ace, Published on Jun 04, 2014
Integrated IR cameras are growing rapidly in popularity, as they help solve a key surveillance problem - poor low light imaging.
However, integrated IR is rarely offered inside PTZs. Indeed, no major Western manufacturer offers an integrated IR PTZ. Recently, though, a number of Asian manufacturers have started to offer these models.
As part of our Dahua HD CVI test, we paid ~$450 for a 720p HD, 20x optical zoom, integrated IR PTZ [link no longer available], rated for 100m IR range. That is quite a price point, considering many Western manufacturers fixed IR IP cameras are more expensive than that.
In this report, we share our test findings of this integrated IR PTZ vs an Axis Q series PTZ.
The image below shows, left to right, the IR PTZ itself, the IR LED pattern and an excerpt of a person being tracked by the IR PTZ:
These are our key findings from this test:
- Long Range: Infrared illumination from the PTZ illuminated subjects at 450'+ (~137m) in the dark, much further than the specified 100m range.
- IR illumination responded quickly to changes in zoom level, adjusting which IR LEDs are used and the power of each set to change angle of illumination.
- Autofocus Problems: IR PTZ frequently failed to properly autofocus while tracking subjects or changing presets, with the process taking 5 seconds or more, most prevalent at night with IR on.
- Below 1 lux, the IR PTZ was easily able to see subjects at up to 500' with recognizable details up to 300'. The non-IR HD PTZ (an Axis Q6045-E [link no longer available]) was unable to see subjects even at 50' at this light level.
- At night with parking lot lights on, ~5 lux at 50', the IR PTZ also outperforms the non-IR PTZ, which is able to detect the reflective test chart up to ~100', but shows no details of the subject.
- IR PTZ was unable to capture license plates at any range due to IR overexposure. Like other integrated IR cameras, reducing shutter speed allowed plate capture but darkened the rest of the image, making it unusable.
In installations with little to no ambient lighting, integrated IR PTZs provide images at ranges where traditional PTZs produce none. However, slow and/or inaccurate autofocus in the Dahua integrated IR PTZ made seeing finer details difficult and operation cumbersome, even when using preset locations. Finally, if license plate capture is a key requirement, potential overexposure is a concern.
Overall, though, while PTZs are in decline, integrated IR is clearly one option that would help improve the usability and viability of PTZs for operator controlled scenarios.
In this video we review the physical construction of the SD6C120I-HC, most notably the 6 LEDs on the camera's face, which are switched on/off depending on camera zoom level.
This short video shows the IR LEDs adjusting as the camera is zoomed from its telephoto to wide angle limits. The side LEDs are used for long distance, and can be seen adjusting down as the lower two LEDs (used for wider angle, shorter distance) increase in power.
In this video we follow a subject from the camera location to ~500' and back, with several highlights worth noting:
- IR illumination pattern evenly covered the field of view at various ranges, with overexposure only present very close to the camera (~10' and closer).
- IR illumination range exceeded specifications (100m), illuminating our subject well at 450'/~137m and beyond.
- Autofocus, notably slower than other PTZs in daylight, was especially slow when using IR, occasionally requiring focus to be adjusted via PTZ controls.
Parking Lot Performance
We tested the 720p integrated IR PTZ against the 1080p Axis Q6045-E in a 400'+ parking lot to test relative performance. Light levels ranged from about 0.1 to 0.6 lux on target, depending on the subject's distance from building lighting, seen in the FOV below:
At ~50', our closest tested range, the IR PTZ displays clear details of our subject's face with the test chart legible to line 6/7. The 1080p model is produces no usable image at this light level.
Moving to 100', IR power is still strong, with details of the subject and chart very similar.
At ~250', we have reached the camera's maximum optical zoom level, and its ability to fine focus is reduced somewhat, with our subject appearing blurry, though 3-4 lines of the chart are still legible.
Finally, at 420', visibility of the subject is greatly reduced, but line 1 of the chart is still moderately legible.
License Plate Capture Performance
Next, we tested at each distance with a car to check license plate capture capabilities of each camera. At 50', the IR PTZ overexposes the plate, completely washing out the numbers, while the 1080p PTZ gets a clear capture due only to the car's license plate lights. Iris and shutter speed may be adjusted in the IR PTZ to reliably capture, but this darkens the rest of the scene so as to be unusable.
At 100', relative performance is the same, with the Axis PTZ capturing again.
At ~250' and beyond, PPF drops too low for the Q6045-E to capture. The IR PTZ remains overexposed.
Next we tested the cameras during the day at each location from our nighttime tests. In the daytime, both cameras provide similar details at ~50' range, though the 1080p model is able to read 3-4 lines further, into the very small text at the bottom of the chart (line 10/11 vs. 7/8).
At 100', performance is similar.
At ~250', we have reached both cameras' maximum zoom range. The Axis Q6045-E has some issues focusing at this range, impacting clarity of the subject and chart, though the chart is still more legible than the 720p IR PTZ.
Finally, at 420', performance of the Axis PTZ worsens, reducing details of the subject, though it is still able to read to line 5/6 of the chart versus 3/4 in the 720p IR PTZ. Details of the subject are similar.
Unlike nighttime, both cameras are easily able to capture a license plate of a moving vehicle during the day, even at maximum range tested (~420').
Open Field Performance
Next, we tested the cameras in an open field bordered by vegetation on both sides to show performance in this scenario, with more ambient light on the target (~8 lux at near ranges):
With outdoor lights on, about 5 lux on target, the IR PTZ easily outperforms the 1080p model, with recognizable details of our subject and legibility of the test chart down to line 6/7. The 1080p PTZ is only marginally able to see the subject, and the test chart is legible only to line 3.
At 100', the IR PTZ delivers similar details, while the Axis PTZ displays only an outline of the subject and chart.
At 300', both cameras have reached their maximum optical zoom range. IR power from the 720p PTZ is notably dimmer, but still delivers some details of the subject with the chart legible to line 3.
Finally, at 480', IR power is further decreased though the subject is still easily visible, albeit without details.
Cameras were tested using default settings unless otherwise specified, 30 FPS H.264.
- Dahua SD6C120I-HC 720p HDCVI IR PTZ [link no longer available]
- Axis Q6045-E [link no longer available]: Firmware 126.96.36.199