The lens is an extremely important part of the CCTV system, usually seen as the camera CCD optical coupling into the imaging device inseparable from the right hand. Now, the number of market CCTV lens manufacturers and lens types are very much, after improving the latest features contained in the special lens is constantly introduced. Like the aspherical lens, we can often contact today, is one of such innovative products. It has broken the CCTV lens industry's conventional, revolutionizing the traditional production process of the lens.
There are many different kinds of surveillance camera and consumer monitoring camera usually M12 interfaces or M16, according to the focal length, commonly used is 2.8 mm, 3.6 mm, 4 mm, 6 mm, 8 mm, 12 mm, etc. Fisheye panoramic surveillance lens and wide aperture surveillance lens gradually occupy an important position in the surveillance market.Tesoo photoelectric monitoring lens product line is rich, aperture F1.0~F2.5, pixel VGA~4K, focal length 0.9mm~25mm, chip size 1/4 "~1/1.7".
Most well-known brands now more than use special high-strength plastic as a shell, in order to reduce the weight of the lens, reduce the thermal expansion and contraction phenomenon is not obvious in the case of large changes in outdoor temperature, to ensure that the location of the lens remains unchanged, to ensure the accuracy of the same. High-strength plastic shell in the production process of high mold costs, complex technology is not easy to be counterfeited. While the metal shell is easy to be counterfeit processing.
The coating process directly affects the imaging effect of the lens, from the human eye to judge the general lens course light violet color, the initial can be concluded that the thickness of the coating moderate to achieve the best light transmission effect. The coating process should not only have advanced and excellent equipment but also the mastery of the coating time is very important, in less than a second it may change to other colors, the operator's experience and grasp of time put forward high requirements. the normal thickness of CCTV lens coating (540 nm ± 20), too thick or too thin can not achieve the best light transmission effect. Due to differences in the level of technology, there are some lenses in the many times after the wipe coating will fall off affect the normal use of the lens.
CCTV lens material selection is the key to lens processing. Lens glass is too hard too soft or lead content is too high can not achieve the best results. The lens uses a lead-free synthetic low-dispersion low-refraction Perspex lens, not only strong light transmission capacity and environmental protection.
Good CCTV lenses have a slight sense of resistance when rotating the knob in focus, not easy to deviate from the focus after adjusting to the appropriate position. The poorer lens focus knob is very loose, a slight movement will deflect the focus. Really good lenses are coated with special mineral oil produced in Japan on the inner wall, it is not easy to flow and has strong lubrication capacity. And other oil added to apply less can not achieve the role of lubrication, add more and will flow inside the lens, sometimes blocking the automatic aperture feathered blade caused by the automatic aperture can not be properly opened and closed.
CCTV lens internal structure is very precise, its technical content is also relatively high, especially the large fixed zoom lens. So targeted selection of the right lens becomes critical. Due to the length of the article, so only the more important topics are listed for analysis, description, I hope that you can help to determine how good or bad a lens.
According to the size of the chip (sensor size): 1/1.8 "surveillance lens, 1/2.5" CCTV lens, 1/2.9 "surveillance lens, 1/2.7" CCTV lens, 1/3 "Surveillance lens, 1/4" surveillance lens
According to the pixel: VGA surveillance lens, 2MP surveillance lens (1080p surveillance lens), 3MP surveillance lens, 4MP surveillance lens, 5MP surveillance lens, 8MP surveillance lens (4K surveillance lens), 12MP surveillance lens according to the interface: M12 surveillance lens, CS interface surveillance lens, C interface surveillance lens according to the focal length: 1.44mm surveillance lens, 2.8mm CCTV lens, 3.6mm surveillance lens, 4mm surveillance lens, 6 mm CCTV lens, 8mm surveillance lens, 12mm surveillance lens, 16mm surveillance lens, 25mm surveillance lens, 50mm surveillance lens, etc. According to the characteristics of parameters: blacklight surveillance lens (F0.9 surveillance lens, F1.0 surveillance lens, F1.2 surveillance lens), starlight surveillance lens (F1.4 Monitor lens, F1.6 monitor lens)