Wide-angle photographic objective
AssigneeLeica Camera AG
InventorsStefan ROTH, Kathrin KELLER
Life of this patent
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Abstract
A wide-angle objective in accordance with the invention comprises, in an order from an object-side end to an image-side end, a front group of total positive refractive power having at least four lenses; a middle group of total positive refractive power having at least three lenses; and a rear group of total positive refractive power having at least three lenses, wherein the quotient of the focal length of the front group and the total focal length of the objective amounts to between 2.28 and 2.79, the quotient of the focal length of the middle group and the total focal length of the objective amounts to between 3.02 and 3.69, and the quotient of the focal length of the rear group and the total focal length of the objective amounts to between 3.50 and 4.29.
Claims30
-23. (canceled)
A wide-angle photographic objective comprising, in sequence from an object-side end to an image-side end:
- a front group of total positive refractive power having at least four lenses;
- a middle group of total positive refractive power having at least three lenses;
- and
- a rear group of total positive refractive power having at least three lenses, wherein the quotient of the focal length of the front group and the total focal length of the objective amounts to between 2.28 and 2.79, the quotient of the focal length of the middle group and the total focal length of the objective amounts to between 3.02 and 3.69, and the quotient of the focal length of the rear group and the total focal length of the objective amounts to between 3.50 and 4.29.
Dependencies are inferred from the claim text.