Patent ID: 11971609
Assignee: LARGAN PRECISION CO., LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 1:
2. The photographing optical system of claim 1, wherein the focal length of the seventh lens element is f7, the focal length of the eighth lens element is f8, the Abbe number of the first lens element is V1, the Abbe number of the second lens element is V2, the Abbe number of the third lens element is V3, the Abbe number of the fourth lens element is V4, the Abbe number of the fifth lens element is V5, the Abbe number of the sixth lens element is V6, the Abbe number of the seventh lens element is V7, the Abbe number of the eighth lens element is V8, the Abbe number of the i-th lens element is Vi, the refractive index of the first lens element is N1, the refractive index of the second lens element is N2, the refractive index of the third lens element is N3, the refractive index of the fourth lens element is N4, the refractive index of the fifth lens element is N5, the refractive index of the sixth lens element is N6, the refractive index of the seventh lens element is N7, the refractive index of the eighth lens element is N8, the refractive index of the i-th lens element is Ni, the minimum value of Vi/Ni is (Vi/Ni)min, and the following conditions are satisfied:

−4.0<f8/f7<−0.60; and

6.0<(Vi/Ni)min≤11.65, wherein i=1, 2, 3, 4, 5, 6, 7 or 8.