Can digital SLR cameras achieve infrared photography?

Principle of infrared photography

Visible light in the spectrum ranges from 380nm to 780nm, including red, orange, yellow, green, cyan, blue and purple, while infrared light waves range from about 680 nm to 1000 nm. Infrared photography filters out visible light through infrared filters, so that the image sensor can only be sensitive to infrared light to produce images.

Infrared filter: filters and cuts off visible light and allows infrared light to pass through. Infrared filters with different wavelengths can get pictures with different effects. For example, with filters of 760nm, 850nm and 950nm, the bright details with obvious infrared features in the picture will be displayed in different degrees. The longer the wavelength of the infrared filter, the greater the contrast.

Infrared photography in the digital age can be achieved in the following three ways:

1. Remove the low-pass filter in front of the camera CCD or CMOS and replace it with an infrared filter in a certain band you like.

2. Remove the low-pass filter in front of the camera CCD or CMOS, replace it with transparent glass, and add various kinds in front of the lens when shooting. Band infrared filter, this is the latest gameplay.

3. Without changing the camera, add an infrared filter directly in front of the camera lens that is sensitive to infrared or has "night shooting mode". The former has a long exposure time and must be shot with a tripod? .

Traditional infrared photography relies on infrared special film, only black and white film, which is expensive to develop in specific places. The CCD or CMOS of digital cameras can sense infrared rays, and most of them are equipped with infrared filters in front, so we can't see the infrared effect.