Medium-telephoto interchangeable fixed-focus lens

Abstract

A middle-long distance shooting exchangeable prime lens comprises a first lens group and a second lens group which are arranged orderly from the object side to the image side, wherein when a shot object moves from the infinity to the near distance, the first lens group is fixed, while the second lens group moves from the image side to the object side to focus. The first lens group is the glued lens having the positive focal power or is composed of two individual lens having the positive focal power and the negative focal power, the second lens group comprises a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens and a sixth lens which are arranged orderly, wherein the second lens, the third lens and the sixth lens have the positive focal power, and the fourth lens and the fifth lens have the negative focal power; the fifth lens is a glued lens, and the sixth lens is an aspheric lens. The middle-long distance shooting exchangeable prime lens of the present invention is reasonable in design, weakens a breath effect in a rear group floating focusing manner, also can reduce the distortion, and satisfies the lens demands of a high-resolution film camera.

Description

technical field [0001] The invention relates to a technology in the field of video and film shooting, in particular to a medium-telephoto interchangeable fixed-focus lens. Background technique [0002] Cine lenses are lenses used for filming movies. Cine lens not only has the top optical quality, but also its mechanical structure design fully takes into account the professional needs of film production, so it is very professional. However, due to the high difficulty of designing and manufacturing movie lenses, no company in China has launched a real movie shooting lens so far. The existing camera lenses have the following deficiencies: 1) The resolution is not high: the resolution of movie cameras can reach 6K or 8K at present, but almost all camera lenses on the market have low resolution and cannot match the use of high-resolution cameras ;2) Obvious vignetting: Due to the limitation of physical laws (mainly the laws of reflection and refraction) and the limitation of le...

AI Technical Summary

Problems solved by technology

However, due to the high difficulty in designing and manufacturing movie lenses, no company in China has launched a real movie shooting lens so far.

The existing camera lenses have the following deficiencies: 1) The resolution is not high: the resolution of movie cameras can reach 6K or 8K at present, but almost all camera lenses on the market have low resolution and cannot match the use of high-resolution cameras ;2) Obvious vignetting: Due to the limitation of physical laws (mainly the laws of reflection and refraction) and the limitation of lens coating level, all lenses will have vignetting more or less; and the control of vignetting by camera lens is not as good as that of movie lens Strict, so the vignetting is more obvious, which cannot meet the needs of video and movie shooting; 3) Large distortion: The picture distortion of dynamic images is often more obvious than that of still photos. Once the pincushion or barrel distortion appears in the picture when there are dynamic elements It will appear immediately, and it will be more serious when the camera's subjective perspective moves; if there is too obvious distortion in the field of vision of the theater audience, it may cause motion vertigo; so the image field of the movie lens must be as flat as possible; And because the camera lens often does not control the distortion enough, it cannot meet the high requirements of the movie lens on the distortion; 4) The breathing effect is obvious: the breathing effect will be produced during the focusing process of the lens. For the camera lens, the breathing effect is almost undetectable. In addition to changes in the composition of the subject, the picture is not affected by the breathing effect; and for film production, it is very common to follow the focus within the picture or shift the focus between different subjects, so the requirements for suppressing the breathing effect are very high. The camera lens does not meet the requirements

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