A high luminous flux Halpha band ultra-wide angle lens

Abstract

The present invention discloses a high luminous flux Halpha band ultra-wide angle lens, which includes a front lens group and a rear lens group. The aperture stop is located between the front lens group and the rear lens group. In the front lens group, lens L1 is a negative meniscus lens, lens L2 is a negative biconcave lens, lens L3 is a biconcave negative lens, lens L4 is a biconvex positive lens, and lens L5 is a biconvex positive lens. The combined focal length f 前 of the front lens group is 60.878 ± 2 mm. In the rear lens group, lens L6 is a biconcave negative lens, lens L7 is a biconvex positive lens, lens L8 is a biconvex positive lens, lens L9 is a biconvex positive lens, and lens L10 is a biconvex positive lens. The combined focal length f 后 of the rear lens group is 88.576 ± 2 mm. The narrowband filter is placed at the aperture stop position. The high luminous flux Halpha band ultra-wide angle lens of the present invention has 4 times the light passing ability compared with the traditional wide-angle lens, and the image quality is uniform in the field of view. The angles of the light rays incident on the filter in each field of view are similar, which is more suitable for narrowband imaging with a filter.

Description

Technical Field

[0001] The present invention belongs to the technical field of wide-angle lens optical design, and particularly relates to an ultra-wide-angle lens with high luminous flux and in the Halpha band. Background Art

[0002] The Halpha band plays an important role in fields such as atmospheric observation. However, for general wide-angle lenses, the focal length ≤ 16 mm, and the general focal ratio (focal length / aperture) is 2.8. When observing with such an optical lens, the clear aperture is about 6 mm, and the light-gathering ability is limited. If an Halpha band narrowband filter is used again, it will cause a further decrease in the system's light transmission. In order to obtain excellent low-light detection ability, although an EMCCD - low-light detection camera with high quantum response efficiency can be used to compensate for the lack of light-gathering ability, the target surface of the EMCCD is small and the number of pixels is small (1k×1k), which will cause a problem of insufficient resolution. Therefore, an ultra-wide-angle lens with high light transmission ability is needed. Summary of the Invention

[0003] In order to solve the above problems existing in the prior art, the present invention provides an ultra-wide-angle lens with high luminous flux in the Halpha band.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] An ultra-wide-angle lens with high luminous flux in the Halpha band includes a front lens group and a rear lens group. The aperture stop is located between the front lens group and the rear lens group. The front lens group is composed of five lenses, namely lens L1, lens L2, lens L3, lens L4, and lens L5. Among them, lens L1 is a negative meniscus lens with a focal length f1 of -203.857 mm, lens L2 is a negative biconcave lens with a focal length f2 of -101.217 mm, lens L3 is a biconcave negative lens with a focal length f3 of -129.952 mm, lens L4 is a biconvex positive lens with a focal length f4 of 118.828 mm, and lens L5 is a biconvex positive lens with a focal length f5 of 132.984 mm. The combined focal length f of the front lens group 前 is 60.878 mm. The rear lens group is composed of five lenses, namely lens L6, lens L7, lens L8, lens L9, and lens L10. Among them, lens L6 is a biconcave negative lens with a focal length f6 of -53.385 mm, lens L7 is a biconvex positive lens with a focal length f7 of 68.371 mm, lens L8 is a biconvex positive lens with a focal length f8 of 69.216 mm, lens L9 is a meniscus negative lens with a focal length f9 of -103.592 mm, and lens L10 is a plano-convex positive lens with a focal length f 10 is 127.306 mm. The combined focal length f of the rear lens group 后It is 88.576 mm, and a narrow-band filter is placed at the position of the diaphragm.

[0006] Furthermore, the radius of the diaphragm is less than 22 mm.

[0007] Furthermore, lenses L6 and L7 are doublet lenses, and the combined focal length f 67 is -349.439 mm, and lenses L8 and L9 are doublet lenses, and the combined focal length f 89 is 213.576 mm.

[0008] Furthermore, the narrow-band filter is a 2-inch narrow-band filter.

[0009] Furthermore, the optical system of the high-flux Halpha-band ultra-wide-angle lens has a focal ratio of F2 and a field of view of 160°.

[0010] Compared with the prior art, the beneficial effects of the present invention are:

[0011] (1) The high-flux Halpha-band ultra-wide-angle lens of the present invention has 4 times the light-passing ability compared with the traditional wide-angle lens (16mm F2.8), and the image quality is uniform within the field of view.

[0012] (2) The high-flux Halpha-band ultra-wide-angle lens of the present invention reserves a diaphragm position to place a 2-inch narrow-band filter, and makes the light rays in each field of view uniformly collimated and incident on the planar filter, which is more suitable for narrow-band imaging in the Halpha band. Description of the Drawings

[0013] Figure 1 is a schematic structural diagram of the high-flux Halpha-band ultra-wide-angle lens;

[0014] Reference numerals: 1 - lens (L1); 2 - lens (L2); 3 - lens (L3); 4 - lens (L4); 5 - lens (L5); 6 - lens (L6); 7 - lens (L7); 8 - lens (L8); 9 - lens (L9); 10 - lens (L10); 11 - filter; 12 - image plane. Detailed Embodiments

[0015] The present invention will be further described in detail below with reference to the drawings.

[0016] Aiming at the problems of limited light-passing and light-gathering capabilities of traditional wide-angle lenses, this embodiment provides a high-flux Halpha-band ultra-wide-angle lens that has 4 times the light-passing ability compared with traditional wide-angle lenses, with uniform image quality within the field of view and being more suitable for narrow-band imaging.

[0017] As Figure 1As shown in the figure, the high - flux Halpha - band ultra - wide - angle lens of this embodiment includes two lens groups, the front group consists of 5 lenses, and the rear group consists of 5 lenses. A 2 - inch filter can be placed at the position of the middle diaphragm to achieve narrow - band observation imaging. The field of view of this high - flux Halpha - band ultra - wide - angle lens is 160°, the focal ratio is F2, and it is suitable for imaging in the 0.558μm - 0.6563μm band.

[0018] Specifically, the 5 lenses of the front - group lens include lens (L1) 1, lens (L2) 2, lens (L3) 3, lens (L4) 4, and lens (L5) 5. Among them, lens (L1) 1 is a negative meniscus lens with a focal length f1 of - 203.857mm, lens (L2) 2 is a negative biconcave lens with a focal length f2 of - 101.217mm, lens (L3) 3 is a biconcave negative lens with a focal length f3 of - 129.952mm, lens (L4) 4 is a biconvex positive lens with a focal length f4 of 118.828mm, lens (L5) 5 is a biconvex positive lens with a focal length f5 of 132.984mm, and the combined focal length f of the front group 前 = 60.878mm.

[0019] Specifically, the 5 lenses of the rear - group lens include lens (L6) 6, lens (L7) 7, lens (L8) 8, lens (L9) 9, and lens (L10) 10. Among them, lens (L6) 6 is a biconcave negative lens with a focal length f6 of - 53.385mm, lens (L7) 7 is a biconvex positive lens with a focal length f7 of 68.371mm, lens (L8) 8 is a biconvex positive lens with a focal length f8 of 69.216mm, lens (L9) 9 is a meniscus negative lens with a focal length f9 of - 103.592mm, lens (L10) 10 is a plano - convex positive lens with a focal length f 10 of 127.306mm. Lenses (L6) 6 and (L7) 7 are doublet lenses, and the combined focal length f 67 = - 349.439mm. Lenses (L8) 8 and (L9) 9 are doublet lenses, and the combined focal length f 89 = 213.576mm. The combined focal length f of the rear group 后 = 88.576mm.

[0020] To expand the application range of this lens, a 2 - inch narrow - band filter 11 is placed at the reserved diaphragm position. The radius of the diaphragm is less than 22mm, and the light rays of each field of view are uniformly collimated and incident on the planar filter 11, reducing the offset of the incident light at different angles of the large - field - of - view optical lens on the filter, which is suitable for the Halpha - band narrow - band shooting scenario.

[0021] The detailed optical layout of this lens is as follows, unit: mm:

[0022]

[0023] The focal ratio of this high-flux Halpha-band ultra-wide-angle lens is F2, the field of view is 160°, and it is suitable for imaging in the 0.558μm - 0.6563μm band. Its light transmission ability is 4 times that of a general wide-angle lens (16mm, F2.8) under the same parameters.

[0024] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high luminous flux Halpha band ultra-wide angle lens, characterized in that, It consists of a front lens group and a rear lens group, and the aperture is located between the front lens group and the rear lens group. The front lens group is composed of five lenses, namely lens L1, lens L2, lens L3, lens L4, and lens L5. Among them, lens L1 is a meniscus negative lens with a focal length f1 of -203.857 mm, lens L2 is a biconcave negative lens with a focal length f2 of -101.217 mm, lens L3 is a biconcave negative lens with a focal length f3 of -129.952 mm, lens L4 is a biconvex positive lens with a focal length f4 of 118.828 mm, and lens L5 is a biconvex positive lens with a focal length f5 of 132.984 mm. The combined focal length f 前 of the front lens group is 60.878 mm. The rear lens group is composed of five lenses, namely lens L6, lens L7, lens L8, lens L9, and lens L10. Among them, lens L6 is a biconcave negative lens with a focal length f6 of -53.385 mm, lens L7 is a biconvex positive lens with a focal length f7 of 68.371 mm, lens L8 is a biconvex positive lens with a focal length f8 of 69.216 mm, lens L9 is a meniscus negative lens with a focal length f9 of -103.592 mm, and lens L10 is a plano-convex positive lens with a focal length f 10 of 127.306 mm. The combined focal length f 后 of the rear lens group is 88.576 mm. A narrow-band filter is placed at the aperture position.

2. The super-high luminous flux Halpha band ultra-wide-angle lens according to claim 1, wherein The size radius of the diaphragm is less than 22 mm.

3. The high luminous flux Halpha band ultra-wide angle lens according to claim 1, characterized in that The lenses L6 and L7 are doublet lenses, and the combined focal length f 67 is -349.439 mm. The lenses L8 and L9 are doublet lenses, and the combined focal length f 89 is 213.576 mm.

4. A high luminous flux Halpha band ultra-wide-angle lens according to claim 1, characterized in that, The narrowband filter is a 2-inch narrowband filter.

5. The high luminous flux Halpha band ultra-wide angle lens according to claim 1, characterized in that, The optical system of the high-flux Halpha-band ultra-wide-angle lens has a focal ratio of F2 and a field of view of 160°.

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