We all know that the image quality of different industrial lenses is not the same. Aberration is an important factor affecting image quality. When choosing an industrial lens, aberration is also the first consideration. Common industrial lens aberrations mainly include the following:

1. Spherical aberration: a monochromatic conical beam emitted from an object point on the main axis to the optical system, after being refracted by the optical series, if the original beams with different aperture angles cannot meet at the same position on the main axis, even in the At the ideal image plane on the main axis, a diffuse light spot (commonly known as the circle of confusion) is formed, and the imaging error of this optical system is called spherical aberration.

2. Coma: A monochromatic conical beam emitted to the optical system from an off-axis object point located outside the main axis, after being refracted by the optical series, if it cannot form a clear point at the ideal image plane, it will If it forms a comet-shaped spot with a bright tail, the imaging error of this optical system is called coma.

3. Astigmatism: The oblique monochromatic conical beam emitted to the optical system from an off-axis object point located outside the main axis cannot form a clear image point after being refracted by the optical series, but can only form a clear image point. Dispersed spot, the imaging error of this optical system is called astigmatism.

4. Field curvature: the clear image formed by the optical system of a plane object perpendicular to the main axis, if it is not in an image plane perpendicular to the main axis, but on a curved surface that is symmetrical with the main axis, that is, the optimal image plane is A curved surface, the imaging error of this optical system is called field curvature. When the image in the center of the screen is clear, the image around the screen is blurred; and when the image in the center of the screen is clear, the image in the center of the screen starts to blur again.

5. Distortion: The straight line outside the main axis in the plane of the subject becomes a curve after being imaged by the optical system, and the imaging error of this optical system is called distortion. Distortion aberrations only affect the geometry of the image, not the sharpness of the image. This is the fundamental difference between distortion and spherical aberration, coma, astigmatism, field curvature.

6. Chromatic aberration: A beam of white light is emitted from a white object to the optical system. After being refracted by the optical system, the light of each color cannot converge on one point, and a color image spot is formed, which is called chromatic aberration. The reason for chromatic aberration is that the same optical glass has different refractive indices for light of different wavelengths, the refractive index of short-wave light is large, and the refractive index of long-wave light is small.