The Difference Between Infrared and Night Vision
The visible light that can be seen by the human eye is arranged according to the wavelength from long to short, in order of red, orange, yellow, green, cyan, blue, and purple. The wavelength range of red light is 0.62-0.76 μm; the wavelength range of purple light is 0.38-0.46 μm. Light with a shorter wavelength than violet light is called ultraviolet light, and light with a longer wavelength than red light is called infrared light, which cannot be seen with the naked eye. Because digital cameras use CCDs to sense all light (visible light, infrared light, ultraviolet light, etc.), this causes the captured image to be very different from the image produced by our naked eyes only seeing visible light. In order to solve this problem, an infrared filter is installed between the lens and the CCD in the digital camera. The images seen are consistent.
Infrared night vision, that is, in the night vision state, the digital camera will emit infrared light that is invisible to the naked eye to illuminate the object being photographed, turn off the infrared filter, and no longer block the infrared rays from entering the CCD. After the infrared rays are reflected by the object Entering the lens for imaging, what we see at this time is the image formed by the reflection of infrared rays, not the image formed by the reflection of visible light, that is, at this time, we can capture images that cannot be seen by the naked eye in a dark environment.
JVC's approach to "night vision" uses a color digital night eye feature. This function is similar to Panasonic's color night vision function. Since it uses a slow shutter speed, it is best to use a tripod when shooting. It is difficult to obtain a good picture with a hand-held method. It is more suitable for shooting color pictures that do not move. As with the Panasonic's Color Night Sight feature, when shooting moving subjects, images tend to smear and appear choppy.
It is worth mentioning that in order to meet the needs of the market, in addition to its traditional infrared night shooting and super infrared night shooting functions, Sony has also newly developed a color slow shutter function, which is compatible with Panasonic color night vision and JVC color digital cameras. The function of night eye is similar, it is suitable for shooting non-moving color images, this function is only used in the state of video recording, and cannot be used for shooting still images. Although the image has become in color, there are problems of smearing and intermittent picture.
The "night vision" method adopted by Panasonic digital video cameras is: "color night vision". The color night vision function uses the brightness of 1LUX (when the shutter speed is controlled at 1/2 second) to brighten the subject to be photographed. The color night vision camera does not emit infrared rays like the infrared night camera models. It does not emit any light, but uses the method of prolonging the exposure time of the CCD, so that the charge generated by the light on the CCD is gradually accumulated incrementally. The circuit of the digital camera performs high-gain operation to complete the "night vision" function. Its characteristic is that there should be at least 1LUX of light (about the brightness of a candle) at the shooting location. Because it is not infrared shooting, the pictures it takes are in color, which is better than Sony’s digital cameras. Color images are better than Looks nice in black and white. However, due to the extended exposure time of the CCD, the captured pictures are not continuous, and there will be a phenomenon of picture smearing
