Manufacturer of spherical lens——Ircut filter is divided into reflection filter and absorption filter
The reflective filter has higher transmittance and lower reflection in the visible region, but the opposite is true in the near-infrared region. Therefore, when the camera is shooting at an angle, the infrared light will produce a large offset and reflect. When the light is reflected by the lens group many times, it will form a halo on the photo, which makes the photo (image) appear reddish.
The absorption filter is made of blue glass, which is an optical absorption material. The copper ions in the glass can absorb the infrared rays, and there is no large reflection. When the camera is shooting at an angle, the light will pass through the blue glass and will not form a halo on the photo after being reflected by the lens group for many times, so that the photo (image) color reproduction is good.
However, blue glass has its own disadvantages, such as less choice of thickness, low hardness and environmental constraints. Therefore, KDS large vacuum introduces a new absorption type photoresist to replace blue glass, and surpasses blue glass in color reproduction through the unique technology of KDS large vacuum.
