In the machine vision system, the high-definition industrial lens is an important component. The quality of the industrial lens plays a key role in the image quality. It has an impact on several most important indicators of the image quality, including: resolution, contrast, depth of field and various kind of aberration. Therefore, the selection of industrial lenses needs to be carefully considered. First, you need to understand the meaning of various parameters of industrial lenses, in order to better judge the quality of the lens.
Basic parameters of industrial lenses
1. Resolution: The resolution of an industrial lens refers to the number of black and white line pairs that can be resolved within a 1 mm pitch on the imaging plane. The unit is "line pairs/mm". Pixel, 8-megapixel, 10-megapixel and other resolution lenses are available for different customers to choose from.
2. Field of view: The range that the lens imaging can cover, it can be the range that can be seen on the monitor, or the maximum range that the digital image output by the device can cover.
3. Maximum/minimum working distance: the range of the distance from the objective lens to the detected object, the system cannot image correctly if it is less than the minimum working distance and greater than the maximum working distance.
4. Depth of field: The distance from the closest point to the farthest point in the scene that can produce a clearer image, the longer the depth of field, the larger the range that can be clearly presented.
5. Distortion rate: Industrial lenses are usually distorted due to the perspective of the optical lens. Geometric distortion refers to the difference in magnification at different positions within the image range due to lens reasons. Geometric distortion mainly includes radial distortion and tangential distortion. Such as pincushion or barrel distortion.
6. Aperture and F value: Aperture industrial lenses consist of several extremely thin metal sheets, through which light can pass. Control the amount of light entering the industrial lens by changing the size of the hole. The wider you open the aperture, the more light comes in through the industrial lens. The value of the aperture is usually expressed in f/#.
7. Focal length, back focal length: The focal length is the distance from the main surface of the image side to the focal point of the image side. The back focal length refers to the distance from the light leaving the last lens surface of the lens to the photosensitive surface of the sensor, such as 16mm, 25mm, etc.
You may also be interested in the following information