Wide-angle front lens added in front of photographic lens
By adding a front lens group with negative power in front of the photographing lens, the existing lens has solved the problem of small angle and low magnification, achieving a larger photography angle and flexible magnification adjustment, and improving the practicality of the lens.
Patent Information
- Application Number
- CN202411900563.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2025-02-18
AI Technical Summary
The existing photography lenses have a small angle when taking pictures, are not high in adjustment, and are priced at a high price, which cannot meet different needs.
Design a wide-angle front lens added in front of the photographic lens, including the main lens and the front lens group. The front lens group has negative light power and is installed on the object side of the main lens. The axial distance L < 35mm can be used to make the main lens. The lens’s photography angle is increased to 100-180 degrees.
By increasing the photography angle and adjusting the magnification, the large depth of field can be achieved, and the background information can be explained in the case of large magnification, which improves the practicality of the lens.
Smart Images
Figure CN119471990A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of wide-angle front lens of a photographic lens, and in particular to a wide-angle front lens added in front of a photographic lens. Background Art
[0002] The camera lens is an optical component used to generate images in photographic equipment. It is the basic unit of film and television works. In film and television production, a lens refers to the sum of a section of images that the camera continuously captures from the start to the stop. In post-editing, a lens is a group of images between two editing points; in the finished film, a lens refers to the complete segment from the previous optical transition to the next optical transition.
[0003] In recent years, as photographic lenses have become more and more diversified, various types of photographic lenses have been continuously introduced, but there are still some problems. For example, the current photographic lenses often have a small angle when shooting, the adjustable magnification is not high, and the price has always been high, which cannot meet different needs. Therefore, a wide-angle front lens added in front of the photographic lens is needed to solve the above problems. Summary of the invention
[0004] The purpose of the embodiments of the present invention is to provide a wide-angle front lens added in front of a photographic lens to solve the problems mentioned in the background technology.
[0005] The embodiment of the present invention is implemented as follows: a wide-angle front lens added in front of a photographic lens comprises: a main lens and a front lens group, wherein the front lens group has a negative optical focal length and is installed on the object side of the main lens, and the axial distance L of the front lens group is less than 35 mm. The front lens group can increase the photographic angle of the main lens to 100-180 degrees.
[0006] Preferably, the front lens group includes: a first negative lens, a second negative lens, a first positive lens, a second positive lens and a third negative lens, the first negative lens is mounted on the main lens, the second negative lens and the first positive lens are a cemented lens group, the second positive lens and the third negative lens are a cemented lens group, and the axial distance L of the front lens group from the first negative lens surface on the object side to the third negative lens surface is less than 35 mm.
[0007] Preferably, the first negative lens satisfies a focal length of -45mm<f2<-35mm, the second negative lens satisfies a focal length of -15mm<f2<-10mm, the first positive lens satisfies a focal length of 15mm<f2<17mm, the second positive lens satisfies a focal length of 15mm<f2<17mm, and the third negative lens satisfies a focal length of -15mm<f2<-10mm.
[0008] Preferably, the overall effective focal length BEL of the front lens group satisfies -10mm<f<15mm.
[0009] The wide-angle front lens provided by the present invention is added in front of the photographic lens. After the dedicated front lens group is connected to the main lens, the photographic front lens group can retain the entire object field size of the original target surface when converting the target surface to 1.1 inches, 1 inch, or 2 / 3 inches. At the same time, the light aperture can also be flexibly adjusted, so that the angle of the wide-angle front lens in front of the photographic lens is increased to 100-180 degrees when taking pictures. The front lens group can be adjusted to achieve a corresponding magnification, and the practicability is strong. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 Schematic diagram of a wide-angle front lens added in front of a photographic lens.
[0011] In the accompanying drawings: 1-main lens, 2-front lens group, 21-first negative lens, 22-second negative lens, 23-first positive lens, 24-second positive lens, 25-third negative lens. DETAILED DESCRIPTION
[0012] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the present invention.
[0013] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.
[0014] See also Figure 1 The embodiment of the present invention provides a wide-angle front lens added in front of a photographic lens, wherein the wide-angle front lens added in front of the photographic lens comprises: A main lens 1 and a front lens group 2, wherein the front lens group 2 has a negative optical focal length and is installed on the object side of the main lens 1, the axial distance L of the front lens group 2 is less than 35 mm, and the front lens group 2 can increase the shooting angle of the main lens 1 to 100-180 degrees.
[0015] By setting the front lens group 2, the shooting angle of the main lens 1 is increased to 100-180 degrees, thereby achieving a large depth of field and being able to explain background information at a large magnification.
[0016] like Figure 1As shown, as a preferred embodiment of the present invention, the front lens group 2 includes: a first negative lens 21, a second negative lens 22, a first positive lens 23, a second positive lens 24 and a third negative lens 25, the first negative lens 21 is mounted on the main lens 1, the second negative lens 22 and the first positive lens 23 are a cemented lens group, the second positive lens 24 and the third negative lens 25 are a cemented lens group, and the axial distance L of the front lens group 2 from the surface of the first negative lens 21 on the object side to the surface of the third negative lens 25 is less than 35 mm.
[0017] like Figure 1 As shown, as a preferred embodiment of the present invention, the first negative lens 21 satisfies the focal length of -45mm<f2<-35mm, the second negative lens 22 satisfies the focal length of -15mm<f2<-10mm, the first positive lens 23 satisfies the focal length of 15mm<f2<17mm, the second positive lens 24 satisfies the focal length of 15mm<f2<17mm, and the third negative lens 25 satisfies the focal length of -15mm<f2<-10mm.
[0018] like Figure 1 As shown, as a preferred embodiment of the present invention, the overall effective focal length BEL of the front lens group 2 satisfies -10mm<f<15mm.
[0019] Working principle: See Figure 1 , represents the combination of the front lens group 2 and the main lens 1 in the present invention. First, the numerical embodiment related to the main lens 1 is described. The structural numerical examples of the main lens 1 followed by the front lens group 2 are shown in Table 1. In this embodiment, n and v are based on the d line.
[0020] Table 1: Example table of structural values of front lens group 2:
[0021] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A wide-angle front lens added in front of a photographic lens, comprising a main lens and a front lens group, characterized in that: The front lens group has negative optical focal length and is installed on the object side of the main lens. The axial distance L of the front lens group is less than 35 mm. The front lens group can increase the photographic angle of the main lens to 100-180 degrees.
2. The wide-angle front lens added in front of the photographic lens according to claim 1, characterized in that: The front lens group comprises: A first negative lens, a second negative lens, a first positive lens, a second positive lens and a third negative lens, wherein the first negative lens is mounted on the main lens, the second negative lens and the first positive lens are a cemented lens group, the second positive lens and the third negative lens are a cemented lens group, and an axial distance L of the front lens group from the first negative lens surface on the object side to the third negative lens surface is less than 35 mm.
3. The wide-angle front lens added in front of the photographic lens according to claim 2, characterized in that: The first negative lens satisfies a focal length of -45mm<f2<-35mm, the second negative lens satisfies a focal length of -15mm<f2<-10mm, the first positive lens satisfies a focal length of 15mm<f2<17mm, the second positive lens satisfies a focal length of 15mm<f2<17mm, and the third negative lens satisfies a focal length of -15mm<f2<-10mm.
4. The wide-angle front lens added in front of the photographic lens according to claim 1, characterized in that: The overall effective focal length BEL of the front lens group satisfies -10mm<f<15mm.