The difference between infrared lens and ordinary lens
The lens has two fingers in film and television, one refers to the optical components used by movie cameras and projectors to generate images, and consists of multiple lenses. A variety of different lenses have different appearance characteristics, and their use in photographic appearance constitutes an optical expression wrist; the second finger is a continuous picture taken from power-on to power-off, or between two editing points. A fragment, also called a ytterbium head. One finger and two fingers are two completely different concepts. In order to distinguish the difference between the two, one is often referred to as an optical lens, and the second is referred to as a lens image.
The main function of the lens is to collect the reflected light from the illuminated object and focus it on the CCD. The image projected onto the CCD is inverted. The camera circuit has the function of inverting it, and its imaging principle is opposite to that of the human eye.
1. Classification of lenses
The classification of lenses can be further classified according to focal length, digital size of focal length, aperture, and zoom adjustment of the lens.
(1) According to the focal length, there are fixed focal length, telescopic, automatic aperture or manual aperture.
(2) According to the size of the focal length, there are standard lens, wide-angle lens, and the number one type of telescope.
(3) According to the aperture classification, there are fixed aperture type (fixed iris), manual aperture type (manual iris), automatic aperture type (auto iris) and other types.
(4) According to the adjustment method of lens telescopic, there are electric telescopic lens, manual telescopic lens and other types.
2. Factors that determine lens quality
(1) The number of lenses used: The combination of multiple types of lenses can increase the color shift and improve the focus, but it will increase the light transmittance.
(2) Lens transmittance: good lens transmittance is more expensive, and poor lens will block the passage of light.
(3) Coating and grinding: The lens coating and grinding technology affect the quality of the lens.
(4) Mechanical installation: The precision of the external mechanical structure of the lens affects the accurate plating and reliability of the lens movement. The poor quality of the mechanical structure will cause adjustment errors and inconsistencies.
The difference between infrared lens and visible light lens First of all, the use of the two is different:
In a monitoring environment that does not require infrared light supplements, an ordinary lens can be used; in a monitoring environment with infrared light supplementation, an infrared lens must be used to achieve a better imaging effect; of course, an ordinary lens is used to supplement the infrared light. You can also see the picture under the light, but the picture will become blurry. I believe everyone has a deep understanding of this.
Secondly, the prices of the two are different:
The price of a professional infrared lens is several times that of an ordinary lens. Because the image of the infrared lens is relatively clear at night and in the morning, the effect is naturally expensive.
The reason why the two functions and prices are so different:
Because the refractive index of glass for different wavelengths of light is different, the position of the focus point will be different. At present, ordinary lenses on the market can gather light with a wavelength difference of about 250nm into the same three-dimensional, that is, 430~650nm or 650~ The light in the range of 900nm can be successfully focused to present a clear image, which is why the ordinary lens is clear in the daytime, and the night vision is blurred. Perhaps the night vision is clear and the daytime is blurred.
The professional-sensing infrared lens uses special lenses, which can gather light in the 430~900nm or even longer wavelength range into the same stereo, so both daytime and night vision are clear. Due to the special lens material, the cost is naturally high.