Large aperture telephoto lens

Abstract

The invention discloses a large aperture telephoto lens. The large aperture telephoto lens comprises a first optical lens with positive focal length, a second optical lens with negative focal length,a third optical lens with positive focal length, a fourth optical lens with negative focal length, a diaphragm, a fifth optical lens with positive focal length, a sixth optical lens with positive focal length, and a seventh optical lens with negative focal length which are orderly arranged from an object side to an image side; one surface, towards the object side, of each of the first optical lensand the fourth optical lens is a convexity; one surface, towards the image side, of each of the third optical length and the fourth optical lens is a concavity; the second optical lens and the seventh optical lens are biconcave optical lenses; the first optical lens, the fifth optical lens and the sixth optical lens are biconvex optical lenses; the focal length of the first optical lens is f1, the focal length of the second optical lens is f2, and the entire focal length of the large aperture telephoto lens is f, (f1/f) is more than 0.55 and less than 0.95, (f1/f2) is more than -0.98 and lessthan -0.38. Compared with the prior art, the maximum aperture of the large aperture telephoto lens can achieve F1.4, the amount of light is sufficient, and a night vision effect is excellent.

Description

technical field [0001] The invention relates to the technical field of optical imaging, in particular to a telephoto lens with a large aperture. Background technique [0002] With the increasing popularity of domestic automobiles and the increasingly serious urban traffic congestion, a large number of effective intelligent traffic command and control systems have emerged in the context of new technologies, and have been widely installed in various cities; and the important equipment of the system One of them is the camera, especially the high-definition large target area camera; from the past to the present, the demand for imaging definition is getting higher and higher, the demand for imaging chips is increasing, and the demand for brightness is increasing. As it becomes stronger and stronger, the optical imaging system that the camera is equipped with needs to be improved accordingly. At present, optical telephoto lenses generally have the disadvantages of small aperture, ...

AI Technical Summary

Problems solved by technology

[0005] 1. The aperture is small, the maximum aperture is F2.8, and the night vision effect is poor;

[0006] 2. The resolution is low, the MTF value is low, and only 5 million or less pixels can be considered;

[0007] 3. Without temperature compensation design, the focus shift image will become blurred in high temperature or low temperature environment

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