Which camera filters visible light, passing infrared

The main function of the infrared filter is to filter out visible light and only allow infrared rays to pass through. Since no visible light passes, the infrared filter looks pure black to the naked eye. If you screw this filter onto a video camera or digital camera with infrared night photography, and turn on the night photography, you will see that the filter becomes transparent after passing through the machine. At this time, if you use a machine with a filter to look at the car glass with a black film, the black glass will have become transparent. The transmittance of this filter to infrared rays reaches over 99%, and the absorption of visible light also reaches over 99%. In other words, what you see with the filtered DC or DV is no longer the world we see with the naked eye, but a pure infrared world. Infrared photography is a major branch of photographic art. Under infrared rays, many substances show various manifestations of infrared. Some white ones can become black, and some black ones can become white. Transparency can Become opaque, and the opaque can become transparent. It should be noted that infrared rays are not X-rays. They can only penetrate some thin chemical fibers, nylon, silk products, paper, etc. In principle, infrared rays are the same as visible light and have all the characteristics of light, such as refraction, scattering, diffraction, etc. These The basic characteristics of light, the characteristics of the object being photographed, and the intensity of the light source determine the final imaging effect of infrared photography. Under the scattering effect, if the material being penetrated is too thick or the surface is uneven, although infrared rays can penetrate it, it cannot produce a clear image, just like frosted glass. The glass itself is purely transparent and light can penetrate, but what is behind the frosted glass I can't see anything clearly. Why? It's because the light is scattered and cannot be imaged at all. Therefore, the things behind the frosted glass cannot be seen clearly. Only if you stick it very close can the image be vaguely formed. Similarly, after some materials are penetrated by infrared rays, they cannot be clearly imaged if they are too thick. This is the basic principle of light and infrared rays and has nothing to do with your machine or filter. But it is worth noting that if the frosted glass is sprinkled with water, it will become transparent again. This is because the angle of light scattering is smaller, so the image can be clearly imaged.

Infrared rays are somewhat different from ordinary light and have some peculiar properties. This makes infrared rays and its filters have professional uses in many industries. You can use our filters to see the words hidden under the ink. , you can see the clues hidden under the paint of some fake cultural relics, and you can also see the handwriting of the letter under the thin cowhide envelope. You can also see through the car glass with a black film. You can find a newspaper, add a filter, turn on night photography, put different shirts on top of the newspaper (some of them cannot be penetrated), and the words on the newspaper will also appear under the shirt. Can be seen clearly.