The basic function of the lens is to achieve beam transformation (modulation). In machine vision systems, the main function of the lens is to image the target on the photosensitive surface of the image sensor. The quality of the lens directly affects the overall performance of the machine vision system, and the proper selection and installation of the lens is an important part of the design of the machine vision system. Below, Shenzhen Industrial Camera Manufacturer TEO will take you to understand the parameters of industrial camera lens?

1. Aperture (Iris)

Expressed by F, measured by the ratio of the focal length f of the lens to the aperture D of the light. Each lens is marked with a maximum F value, for example 8mm / F1.4 represents a maximum aperture of 5.7 mm. The smaller the F value, the larger the aperture, the larger the F value, and the smaller the aperture.

2. Focal Length

The focal length is the distance from the center point of the lens to the sharp image formed on the glue plane. The size of the focal length determines the size of the viewing angle, the focal length value is small, the viewing angle is large, and the range of observation is also large; the focal length value is large, the viewing angle is small, and the observation range is small. According to whether the focal length can be adjusted, it can be divided into two categories: fixed focus lens and zoom lens.

3. Interface (Mount)

The way the lens is connected to the camera. Commonly used include C, CS, F, V, T2, Leica, M42x1, M75x0.75 and so on.

4. Corresponding to the maximum CCD size (Sensor Size)

The maximum CCD chip size that the lens imaging diameter can cover. Mainly: 1/2", 2/3", 1" and 1" or more.

5. Resolution (Resolution)

The resolution represents the ability of the lens to record the details of the object, in terms of the number of black and white lines that can be resolved in millimeters: "pair/mm" (lp/mm). The higher the resolution, the sharper the lens is.

6. Depth of Field (DOF)

Depth of field refers to the range in which the image is still clear within a certain distance before and after the object is focused. The depth of field varies with the aperture value, focal length, and shooting distance of the lens. The larger the aperture, the smaller the depth of field; the smaller the aperture, the greater the depth of field. The longer the focal length, the smaller the depth of field; the shorter the focal length, the greater the depth of field. The closer the subject is to the subject, the smaller the depth of field; the farther away from the subject, the greater the depth of field.

7, Field of View (FOV)

The size of the area actually captured by the camera.

8, Working distance (WD)

The distance from the first working surface of the lens to the object being measured.

9, optical magnification (Magnification, ß)

CCD/FOV, which is the chip size divided by the field of view.

10, back focus (Flange distance)

To be precise, post-focus is a parameter of the camera, which refers to the distance from the camera interface plane to the chip. However, when an online scanning lens or a large-area camera lens is selected, the rear multi-focus is a very important parameter because it directly affects the lens configuration. Cameras from different manufacturers may have different post-focus even if the interface is the same.

11, numerical aperture (NumericalAperture, NA)

The numerical aperture is equal to the product of the refractive index n of the medium between the object and the objective lens and the sine of half the aperture angle of the objective lens (a2), and is calculated as N.A=n*sin a/2. The numerical aperture is closely related to other optical parameters, which is proportional to the resolution and proportional to the magnification. That is to say, the numerical aperture directly determines the resolution of the lens. The larger the numerical aperture, the higher the resolution, otherwise the opposite.

The above is the introduction of the industrial camera lens parameters introduced by TEO. The industrial camera lens parameters are still quite a lot. Different lenses are also very different in terms of image quality. Therefore, the choice of industrial camera lens is also very important.