Wide-angle front lens added in front of photographic lens

Abstract

The utility model relates to the technical field of wide-angle front lenses of photographic lenses, in particular to a wide-angle front lens added in front of a photographic lens, which comprises a main lens and a front lens group, the front lens group has negative focal power and is mounted on the object side of the main lens, and the axial distance L of the front lens group is less than 35mm. The front lens group can increase the shooting angle of the main lens to 100-180 degrees. According to the wide-angle front lens added in front of the photographic lens provided by the utility model, the special front lens group is connected to the rear of the main lens, so that the photographic front group lens can keep all object view sizes of an original target surface during 1.1 inch, 1 inch or 2 / 3 inch target surface conversion, and meanwhile, the clear aperture can be flexibly adjusted; the angle of the wide-angle front lens in front of the photographic lens is increased to 100-180 degrees during photographing, the front lens group can be adjusted to achieve corresponding multiplying power, and the practicability is high.

Description

TECHNICAL FIELD

[0001] The utility model relates to photography lens wide-angle front mirror technical field especially relates to a wide-angle front mirror lens is added in the front of photography lens. BACKGROUND

[0002] ‌Photography lens is the optical component for generating image in photography equipment, and it is the basic unit of film and television works. In film and television production, the lens refers to the sum of a section of picture taken uninterruptedly by the camera from starting to static. In the post-editing, the lens is a group of pictures between two cutting points; in the completed film, a lens refers to the complete segment between the previous optical conversion and the next optical conversion.

[0003] In recent years, with the more and more diversification of photography lens, various photography lenses are constantly innovated, but there are still some problems, for example, the angle of the current photography lens is often small when photographing, the adjustable magnification is not high, and the price is always high, which cannot meet different needs, so a wide-angle front mirror lens is needed to be added in front of the photography lens to solve the above problems. UTILITY MODEL CONTENT

[0004] The purpose of the embodiment of the utility model is to provide a wide-angle front mirror lens added in front of the photography lens to solve the problems mentioned in the background art.

[0005] The embodiment of the utility model is realized in this way, a wide-angle front mirror lens added in front of the photography lens, comprising: a main lens and a front lens group, the front lens group has a negative 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 35mm, and the front lens group can increase the photography angle of the main lens to 100-180 degrees.

[0006] Preferably, 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, the first negative lens is installed 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 surface of the first negative lens to the surface of the third negative lens is less than 35mm.

[0007] Preferably, the first negative lens satisfies focal length-45mm

[0008] Preferably, the overall effective focal length BEL of the front lens group satisfies-10mm

[0009] The wide-angle front lens added in front of the photographing lens can increase the photographing angle of the main lens 1 to 100-180 degrees through the special front lens group connected behind the main lens, the front lens group can be adjusted to achieve the corresponding magnification, and the wide-angle front lens added in front of the photographing lens has high practicability. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 The wide-angle front lens added in front of the photographing lens is a schematic view.

[0011] In the 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 scheme and advantages of the utility model more clearly, the following will be further described in detail by combining with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model, and do not limit the utility model.

[0013] The specific implementation of the utility model will be described in detail in combination with specific examples.

[0014] Please refer to Figure 1 The utility model embodiment provides a wide-angle front lens added in front of the photographing lens, the wide-angle front lens added in front of the photographing lens includes:

[0015] The main lens 1 and the front lens group 2, the front lens group 2 has negative optical power 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 35mm, and the front lens group 2 can increase the photographing angle of the main lens 1 to 100-180 degrees.

[0016] The photographing angle of the main lens 1 is increased to 100-180 degrees through the front lens group 2, so that the large depth of field is realized, and the background information can be realized under the large magnification.

[0017] As Figure 1As shown, as a preferred embodiment of the utility model, the front lens group 2 includes: first negative lens 21, second negative lens 22, first positive lens 23, second positive lens 24 and third negative lens 25, the first negative lens 21 is installed on main lens 1, second negative lens 22 and first positive lens 23 are cemented lens group, second positive lens 24 and third negative lens 25 are cemented lens group, the axial distance L of the front lens group 2 from object side first negative lens 21 surface to third negative lens 25 surface is less than 35mm.

[0018] As shown, Figure 1 As a preferred embodiment of the utility model, the first negative lens 21 satisfies focal length-45mm < f2 < -35mm, the second negative lens 22 satisfies focal length-15mm < f2 < -10mm, the first positive lens 23 satisfies focal length 15mm < f2 < 17mm, the second positive lens 24 satisfies focal length 15mm < f2 < 17mm, and the third negative lens 25 satisfies focal length-15mm < f2 < -10mm.

[0019] As shown, Figure 1 As a preferred embodiment of the utility model, the overall effective focal length BEL of the front lens group 2 satisfies-10mm < f < 15mm.

[0020] Working principle: refer to Figure 1 , indicating the combination of the front lens group 2 and the main lens 1 in the utility model, first, the main lens 1 related numerical examples are described. The structure numerical example of the main lens 1 after the front lens group 2 is shown in table one, in this embodiment, n, v is based on d line.

[0021] Table one: structure numerical example table of front lens group 2:

[0022] Surf STYP Radius Thickness Nd Vd SEMIDIAMETER GLASS OBJ STANDARD Infinity 40 125.6116 1 STANDARD Infinity 0 30.9629 2 STANDARD 161.4776 0.9981 1.516802 64.230624 29.3787 H-K9L 3 STANDARD 18.908 6.8533 26.4 4 STANDARD -43.4881 1.9952 1.781796 37.094648 22.1447 H-LAF7 5 STANDARD 13.0888 6.1834 1.740005 28.291496 19.7641 H-ZF5 6 STANDARD -264.9261 5 19.3863 7 STANDARD 264.9261 6.1834 1.740005 28.291496 16.6887 H-ZF5 8 STANDARD -13.0888 1.9952 1.781796 37.094648 15.6083 H-LAF7 9 STANDARD 43.4881 14.1078 14.2259

[0023] The above only for the preferred embodiment of the utility model has, and does not limit the utility model, any modification, equivalent replacement and improvement etc. within the spirit and principles of the utility model, should be included in the protection scope of the utility model.

Claims

1. A wide-angle front lens for attachment in front of a photographic lens comprising a main lens and a front lens group, characterized in that, The front lens group has negative 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 35mm, and the front lens group can increase the photographing angle of the main lens to 100-180 degrees. 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, the first negative lens is installed 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 surface of the first negative lens to the surface of the third negative lens is less than 35mm.

2. The wide-angle front lens for attachment in front of a photographic lens according to claim 1, characterized in that The first negative lens satisfies the focal length -45mm 3. The wide-angle front lens for attachment in front of a photographic lens according to claim 1, wherein The overall effective focal length BEL of the front lens group satisfies -10mm

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