Difference between HD lens and normal lens

Megapixel cameras have higher requirements for megapixel lenses, CCDs, DSP chips, and even pan/tilt cameras. With the increase in the demand for high-definition lenses in the surveillance market, many customers have started to use megapixel CCDs. The camcorder, while the traditional optical image quality of the lens has not been able to play a high-definition performance of the megapixel lens CCD camera. High-definition lens is of great significance for high-definition surveillance. Compared with ordinary lenses, what are the similarities and differences between the two?

HD lens, also known as megapixel lens

Megapixel lenses, also known as high definition lenses, can be called megapixel shots when they reach 720p. In the past, the monitoring market generally believed that the resolution of interlaced images of 4CIF (704X576) or D1 (720X480) could be called a megapixel lens, while the field of broadcasting and video teleconference put interlaced images of D3 (1920X1080), ie 1080i or The D4 (1280X720) progressive scan image can be referred to as megapixel.

A megapixel camera needs a corresponding megapixel camera to better play the camera's resolution. As far as I know, both lens manufacturers, engineering companies and users have clearly stated that megapixel lenses will become the main trend of the lens. The manufacturers also believe that whether the future lens brands can win in the competition lies in whether they can keep up with the trend of high-definition and launch products that meet market demand. From the actual use of the effect point of view, high-definition lens is also more than ordinary lenses, with different lens products and video cameras, showing the effect is very different. Take traffic monitoring as an example. By using a high-definition camera, you can not only see the license plate, but also see the details of the car and the drivers on the car.

Once a traffic accident occurs, it has a great effect on the investigation and investigation of criminal cases by the Public Security Bureau. However, the popularity of megapixel lenses has also caused manufacturers to face more challenges. First of all, megapixel lenses are higher in design, assembly process, and processing accuracy than ordinary lenses. On the other hand, in the field of surveillance high-definition, many products such as transmission equipment, display equipment, video equipment, etc. High-definition is not ideal, so HDTVs have to enter the ideal sales period and may take 3-5 years.

Difference between HD lens and normal lens

At present, megapixel lenses are more commonly used fixed-focus, manual zoom, power zoom and so on. For security applications in different industries, there are basically more mature applications. For example, in the area of ​​traffic capture, a fixed-megapixel camera is commonly used. What is the difference between a megapixel camera and an ordinary camera?

1, the difference in sharpness

The resolution of the lens at the center of the imaging plane is the highest, and the picture at the edge is relatively poor. While the normal lens can basically satisfy the definition at the center, the sharpness of the edge will be reduced a lot, and the overall definition can meet the requirement of 440,000 pixels for an ordinary camera.

In fact, there are three key factors that determine the sharpness of the lens: 1. Lens material and purity. The less impurities in the lens, the less interference light it produces, the higher the resolution of the picture; 2. The grinding accuracy of the lens. The grinding precision of the lens is determined by the grinding equipment. At present, the difference between the domestic lens and the foreign lens is reflected in this point; 3, the coating accuracy of the lens. Accurate control of the coating process is also one of the determinants of lens definition.

In addition, the use of aspherical lenses for megapixel lenses reduces aberrations, enables compact designs while improving clarity relative to ordinary lenses, and achieves image quality from the center of the image to the periphery through special optical design techniques. High-resolution, high-contrast images provide about 2.5 times more resolution than conventional lenses, ensuring high image quality even when the image is cut or enlarged.

2. Difference in spectral transmittance

The spectral transmission ability of the lens also contributes to the sharpness of the picture. The transmission of wide frequency light will greatly increase the amount of light received by the camera's target surface. Can enhance the contrast and brightness of the picture, and it is richer in the details of the picture.

3, the difference in spectral correction ability

Only wide-spectrum transmission power is not enough for high-definition imaging. If the lens's spectral correction ability is insufficient, part of the wavelength light will not be accurately imaged on the target surface of the camera, resulting in the generation of virtual images. This technique is not possible with ordinary lenses through coating.