Infra-Red “IR” Illuminators
Infrared illuminators are used by lower quality camera manufacturers to provide additional illumination for their camera in low light conditions. They need to due to the low quality lens and CCD imager they use. Unfortunately most of the IR illuminators used by low cost camera manufacturers today have a short range, approximately 6 to 10 feet, and produce a horrible spotlight or tunnel effect that gives lighting in the middle of the image but then fades to almost complete darkness along the outer edges of the image. To compensate for this spotlight effect they'll often times add more IR illuminators or narrow the cameras filed of view.
In addition, infrared radiation can overwhelm a camera's sensor and cause it to misjudge the colors that it is recording. High quality camera manufacturers don't use IR Illuminators but instead use higher quality lenses and CCD imagers. They also use an Infrared Cut-off Filter to filter out the infrared light that the camera picks up during visible lighting conditions. If they didn’t the extra infrared radiation would combine with the visible light to make a lesser quality image. Use of an Infrared Cut-off Filter produces a much cleaner, brighter, and higher quality video image.
Infrared rays can also be damaging to the eyes. The eye does not react to infrared rays produced by an infrared LED; the pupil will not react to protect the retina from the rays. As a result, the retina can easily be damaged from overexposure to infrared light produced by the LED.
Bright natural light which contains Infra-Red causes the eye to blink, the iris to contract, and the viewer to look away. These normal defense mechanisms do not happen when the visible part of the light has been removed, which is exactly what happens in IR Illumination. Your eyes are more sensitive than your skin and over exposure for long periods may result in retinal damage and cataracts.
So, how do you protect yourself? The rule of thumb is to not look directly at the IR source for long periods of time and to work within the Minimum Safe Working Distance which is typically at least half the distance away of the illuminators effective range. For example; if the illuminator used has a range of 12 feet you’ll want to stay at least 6 feet away from it and you never want to look directly at it for prolonged periods of time.
Most manufacturers have guidelines for these devices and it is recommended that you follow them for your customers, installers, and employees.
INTEC does not use IR illuminators in our cameras. We prefer to use improved CCD’s and Lenses to provide a quality image across all lighting conditions.