Optical assembly for a wide field of view camera with low TV distortion
An optical assembly for a wide field of view digital camera includes, from object end to image end, first and second optical groups separated by an aperture stop. The optical assembly is configured to provide images with TV distortion that is less than 16. The first optical group includes two or more lens elements, including a first lens element having a largest diameter among the multiple lens elements to collect light at said wide field of view. The second optical group includes a doublet, which is configured to compensate for oblique aberrational error, and an aspheric lens element, which is configured to compensate for astigmatism error.
1. An aspheric lens element for an optical assembly of a wide field of view point action camera, comprising an optical material including at least one aspheric surface that is configured to compensate for astigmatism error within an optical assembly, and wherein said at least one aspheric surface includes a first surface that includes an approximately 30 microns or less sag and an approximately 25 microns/millimeter or less aspheric sag slope across said first surface, and
wherein the first surface comprises approximately 6-30 microns sag and approximately 7-25 microns/millimeter aspheric sag slope across said first surface, and
wherein the first surface comprises a radius of curvature between approximately 8-10 millimeters.
2. The aspheric lens element of claim 1 , wherein said aspheric lens element comprises a second surface that includes an approximately 30 microns or less sag and an approximately 20 microns or less sag slope across said second surface.
3. The aspheric lens element of claim 1 , wherein said aspheric sag comprises less than approximately 25 microns across said first surface.
4. The aspheric lens element of claim 1 , wherein said aspheric sag comprises less than approximately 23 microns across said first surface.
5. The aspheric lens element of claim 1 , wherein said aspheric sag comprises less than approximately 21 microns across said first surface.
6. The aspheric lens element of claim 1 , wherein said aspheric sag slope comprises less than approximately 25 microns per millimeter across said first surface.
7. The aspheric lens element of claim 1 , wherein said aspheric sag slope comprises less than approximately 20 microns per millimeter across said first surface.
8. The aspheric lens element of claim 1 , wherein said aspheric sag slope comprises less than approximately 15 microns per millimeter across said first surface.
9. The aspheric lens element of claim 1 , wherein said first surface includes a point of inflection of maximum sag at less than approximately 0.85×.
10. The aspheric lens element of claim 1 , wherein said first surface includes a point of inflection of maximum sag at less than approximately 0.8×.
11. The aspheric lens element of claim 1 , wherein said first surface includes a point of inflection of maximum sag at less than approximately 0.75×.
12. The aspheric lens element of claim 1 , wherein said first surface includes a point of inflection of maximum sag at less than approximately 0.7×.
13. The aspheric lens element of claim 1 , wherein said first surface includes a point of inflection of aspheric slope extremum at less than approximately 0.5×.
14. The aspheric lens element of claim 1 , wherein said first surface includes a point of inflection of aspheric slope extremum at less than approximately 0.4×.
15. The aspheric lens element of claim 1 , wherein said first surface includes a point of inflection of aspheric slope extremum at less than approximately 0.3×.
16. An aspheric lens element for an optical assembly of a wide field of view point action camera, comprising an optical material including at least one aspheric surface that is configured to compensate for astigmatism error within an optical assembly, and wherein said at least one aspheric surface includes a first surface that includes an approximately 30 microns or less sag and an approximately 25 microns/millimeter or less aspheric sag slope across said first surface, and
wherein the first surface comprises approximately 6-30 microns sag and approximately 7-25 microns/millimeter aspheric sag slope across said first surface, and
wherein said aspheric lens element comprises a second surface that includes an approximately 30 microns or less sag and an approximately 20 microns or less sag slope across said second surface,
wherein said first surface includes a point of inflection of maximum sag at less than approximately 0.85×.
17. The aspheric lens element of claim 16 , wherein said first surface includes a point of inflection of maximum sag at less than approximately 0.8×.
18. The aspheric lens element of claim 16 , wherein said first surface includes a point of inflection of maximum sag at less than approximately 0.75×.
19. The aspheric lens element of claim 16 , wherein said first surface includes a point of inflection of maximum sag at less than approximately 0.7×.
20. An aspheric lens element for an optical assembly of a wide field of view point action camera, comprising an optical material including at least one aspheric surface that is configured to compensate for astigmatism error within an optical assembly, and wherein said at least one aspheric surface includes a first surface that includes an approximately 30 microns or less sag and an approximately 25 microns/millimeter or less aspheric sag slope across said first surface, and
wherein the first surface comprises approximately 6-30 microns sag and approximately 7-25 microns/millimeter aspheric sag slope across said first surface, and
wherein said aspheric lens element comprises a second surface that includes an approximately 30 microns or less sag and an approximately 20 microns or less sag slope across said second surface,
wherein said first surface includes a point of inflection of aspheric slope extremum at less than approximately 0.5×.
21. The aspheric lens element of claim 20 , wherein said first surface includes a point of inflection of aspheric slope extremum at less than approximately 0.4×.
22. The aspheric lens element of claim 20 , wherein said first surface includes a point of inflection of aspheric slope extremum at less than approximately 0.3×.
23. An aspheric lens element for an optical assembly of a wide field of view point action camera, comprising an optical material including at least one aspheric surface that is configured to compensate for astigmatism error within an optical assembly, and wherein said at least one aspheric surface includes a first surface that includes an approximately 10 microns or less sag and an approximately 25 microns/millimeter or less aspheric sag slope across said first surface, and
wherein the said first surface includes approximately 6-10 microns sag and approximately 7-25 microns/millimeter aspheric sag slope across said first surface, and
wherein the first surface comprises a radius of curvature between approximately 6-10 millimeters.
24. The aspheric lens element of claim 23 , wherein said aspheric sag comprises less than approximately 25 microns across said first surface.
25. The aspheric lens element of claim 23 , wherein said aspheric sag comprises less than approximately 23 microns across said first surface.
26. The aspheric lens element of claim 23 , wherein said aspheric sag comprises less than approximately 21 microns across said first surface.
27. The aspheric lens element of claim 23 , wherein said aspheric sag slope comprises less than approximately 25 microns per millimeter across said first surface.
28. The aspheric lens element of claim 23 , wherein said aspheric sag slope comprises less than approximately 20 microns per millimeter across said first surface.
29. The aspheric lens element of claim 23 , wherein said aspheric sag slope comprises less than approximately 15 microns per millimeter across said first surface.
30. The aspheric lens element of claim 23 , wherein said aspheric lens element includes a second surface that includes an approximately 30 microns or less sag and an approximately 20 microns or less sag slope across said second surface.