Optical assembly for a wide field of view point action camera with a low sag aspheric lens element
An optical assembly for a point action camera with a wide field of view has multiple lens elements configured to provide a field of view in excess of 150 degrees. One or more lens elements has an aspheric surface with an approximately 30 microns or less sag and an approximately 25 microns/millimeter or less aspheric sag slope.
1. An optical assembly for a point action camera having a wide field of view, comprising multiple lens elements including an aspheric surface, configured to provide a field of view in excess of 150 degrees that comprises an inward field curvature of less than 75 microns, wherein the optical assembly comprises from object end to image end:
a. a first convexo-concave meniscus lens;
b. a second convexo-concave meniscus lens;
c. a first convex lens;
d. an aperture stop;
e. a second convex lens;
f. a doublet comprising a first concave lens coupled to a third convex lens; and
g. a fourth convex lens, including at least one aspheric surface.
2. The optical assembly of claim 1 , wherein the inward field curvature comprises approximately 50 microns or less.
3. The optical assembly of claim 1 , wherein the optical assembly has a longitudinal astigmatism that comprises approximately 0.7 mm or less.
4. The optical assembly of claim 1 , wherein said fourth convex lens comprises a convex aspheric object facing surface and a convex or planar image facing surface.
5. The optical assembly of claim 1 , wherein the lateral chromatic aberration is less than approximately five microns.
6. The optical assembly of claim 1 , wherein the first convex lens comprises a convex object facing surface and a convex or planar image facing surface.
7. The optical assembly of claim 1 , wherein the second convex lens comprises a convex or planar object facing surface and a convex image facing surface.
8. The optical assembly of claim 1 , wherein the first concave lens comprises a concave or planar object facing surface and a concave image facing surface.
9. The optical assembly of claim 1 , wherein the third convex lens comprises a convex object facing surface and a convex image facing surface.
10. The optical assembly of claim 1 , wherein the fourth convex lens comprises a convex object facing surface and a convex or planar image facing surface.
11. A digital camera, comprising
A. an optical assembly for a point action camera having a wide field of view, comprising multiple lens elements including an aspheric surface, configured to provide a field of view in excess of 150 degrees that comprises an inward field curvature of less than 75 microns, wherein the optical assembly comprises from object end to image end:
i. a first convexo-concave meniscus lens;
ii. a second convexo-concave meniscus lens;
iii. a first convex lens;
iv. an aperture stop;
v. a second convex lens;
vi. a doublet comprising:
a. a first concave lens; and
b. a third convex lens; and
vii. a fourth convex lens, including at least one aspheric surface;
B. an image sensor disposed approximately at a focal plane of the optical assembly; and
C. a digital camera housing including electronics and a user interface, and containing said optical assembly and said image sensor in optically effective relative disposition.
12. The digital camera of claim 11 , wherein the inward field curvature comprises approximately 50 microns or less.
13. The digital camera of claim 11 , wherein the optical assembly has a longitudinal astigmatism that comprises approximately 0.7 mm or less.
14. The digital camera of claim 11 , wherein said fourth convex lens comprises a convex aspheric object facing surface and a convex or planar image facing surface.
15. The digital camera of claim 11 , wherein the lateral chromatic aberration is less than approximately five microns.
16. The digital camera of claim 11 , wherein the first convex lens comprises a convex object facing surface and a convex or planar image facing surface.
17. The digital camera of claim 11 , wherein the second convex lens comprises a convex or planar object facing surface and a convex image facing surface.
18. The digital camera of claim 11 , wherein the first concave lens comprises a concave or planar object facing surface and a concave image facing surface.
19. The digital camera of claim 11 , wherein the third convex lens comprises a convex object facing surface and a convex image facing surface.
20. The digital camera of claim 11 , wherein the fourth convex lens comprises a convex object facing surface and a convex or planar image facing surface.