摘要 |
A compact F-theta lens suitable for precise mapping and aerial photography has an F# of not more than 4.5 and a full field of view of 60° (high quality field over) 53°. The lens is near-telecentric to less than 6°, apochromatic from 450 nm to 650 nm, and athermal from−15° C. to +40° C. Embodiments have a focal plane diameter of 104 mm and are compatible for use with a CMOS 1.8 gigapixel multiple FPA. In some embodiments the focal length is 101 mm and the back working distance is more than 10 mm. In embodiments the lens includes three groups of optical elements, with an aperture located between the first and second groups. In some of these embodiments, the first group has at least three elements, while the second and third groups have four and three elements respectively, and the diameter of the first two groups, including housing, is less than 65 mm.
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