Infrared cut filters, sometimes called IR filters or heat-absorbing filters, are designed to reflect or block near-infrared wavelengths while passing visible light. They are often used in equipment with bright incandescent light bulbs (such as slides and projectors) to prevent unnecessary heating. Due to the high sensitivity of many camera sensors to near-infrared light, there are also filters used in solid-state (CCD or CMOS) cameras to block infrared light. These filters usually have a blue tint because they also sometimes block some of the light from the longer red wavelengths. IR filters can be transparent, gray, gradient or a variety of different colors.
Unlike the eye, sensors based on silicon (including CCDs and CMOS sensors) have sensitivities extending into the near-infrared. Such sensors may extend to 1000 nm. IR filters are used to alter the light transmitted through the lens to the image sensor to prevent unnatural-looking images. IR-transmitting (passing) filters or removing factory IR-blocking filters are commonly used in IR photography to pass IR light and block visible and UV light. This filter appears black to the eye, but is transparent when viewed with IR-sensitive devices.
Originally, IR filters were used in film photography to enhance black and white photography. By adding filters of different colors, photographers can add depth, improve contrast, and reduce glare that can ruin an image.
A wide variety of filters are available for industrial machine vision. Filters allow you to achieve stunning results, improve the visibility of specific details, and often simplify your machine vision tasks significantly.
For example, a bandpass filter coordinated with the light being used will allow you to filter out the often overwhelming ambient light almost completely. Also, in normal applications, the invisible properties of objects are usually made visible using suitable filters.
CHANCCTV offers you a wide range of different filters for virtually every lens.
940nm Narrow Bandpass
IR650-850nm Dual Bandpass
IR650nm Bandpass
IR800-1000nm Longpass