The day-night dual-pass filter, as an important optical component, is widely used in CCD and CMOS imaging systems, CCTV surveillance systems, and other fields. Its characteristic is that it can capture true color images during the day and clear black-and-white images at night, achieving a dual-use function for switching between black-and-white and color. Additionally, it has the ability to resist strong light and interference from stray light, as well as strong color distortion.
There are two methods to enable color surveillance cameras to sense infrared light under nighttime conditions:
The first method involves covering the infrared light with visible light. In the absence of visible light, the filter by the optical filters manufacturers is removed to allow infrared light to enter, resulting in good image quality. However, this method increases costs and has a high failure rate for the switching mechanism.
The second method involves opening a specific infrared channel on the filter, allowing infrared light with the same wavelength as the infrared lamp to pass through. This is known as a day-night dual-pass filter.
The filter is composed of an optical glass substrate and a filter coating deposited on the optical glass substrate. It can block ultraviolet and infrared rays from mixed light sources, resulting in sharper and clearer images. Additionally, the filter can selectively allow certain parts of the infrared spectrum to pass through based on the characteristics of the infrared lamp, thereby enhancing night vision capabilities.
The day-night dual-pass filter can transmit visible light in the range of 420nm-620nm and infrared light at 850nm, while blocking near-infrared light in the range of 920nm-1100nm. This allows for true color images during the day and clear black-and-white images at night. We provide both long pass filter and short pass optical filter.
Product parameters | Index parameters |
ON/OFF Wavelength | 650nm±10m/850nm±10m/940nm±10m |
Transmission at CWL | >90% |
Through the band (nm) | 400nm~650nm/850nm/940nm |
Product size | 3mm-80mm (Square of round) or custom |
Cut off wavelength | 720nm~760nm/950nm~1050nm |
Blocking | T ≤5% |
Product material | H-K9L, BK7, B270, D263T, JGS1, Float glass etc. |
Surface Quality | 60-40,40-20 |
It is primarily used in CCD chip color cameras and CMOS imaging systems, security surveillance cameras, digital cameras, network cameras, video phones, doorbells, digital telescopes, license plate recognition cameras, and more. Its features include strong resistance to strong light and stray light interference, and reduced color distortion.
Bena Optics is highly recommended for their day-night dual-pass filters, which have earned a solid reputation in the international market for their outstanding quality.
