CANON EF 8-15mm f/4 L Fisheye USM

US 2012/0013996 A1 Example 1 — Canon / Okumura

14 elements / 11 groups
8-15 mm marketed; 8.05-15.14 mm design
f/4 marketed; F/4.12 patent design
180° circular-to-diagonal fisheye coverage
1 glass-molded aspherical surface

Focus Mechanism

Inner focus by translating L12 (element L5, surfaces 9A-10). Close-focus D8/D10 values are paraxial estimates to the official 0.15 m MFD because the patent publishes infinity zoom spacings only.

Optical Elements (14)

ElementTypeGlass
L1Negative MeniscusS-LAH65V (OHARA)
L2Negative MeniscusFCD505 / FCD515 class (HOYA)
L3Biconcave NegativeFCD505 / FCD515 class (HOYA)
L4Biconvex PositiveS-TIH6 (OHARA)
L5Neg. Meniscus (1× Asph)M-TAFD305 (HOYA)
L6Biconvex PositiveS-LAH58 (OHARA) / TAFD33 class
L7Biconcave NegativeS-LAH58 (OHARA) / TAFD33 class
L8Biconvex PositiveS-NSL3 (OHARA)
L9Biconvex PositiveS-FSL5 (OHARA)
L10Negative MeniscusS-LAH58 (OHARA) / TAFD33 class
L11Biconvex PositiveS-FTM16 (OHARA)
L12Plano-Concave NegativeS-LAH60V (OHARA)
L13Biconvex PositiveS-FPL51 (OHARA) / FCD1 class
L14Positive MeniscusS-FSL5 (OHARA)

Analysis

Detailed analysis available in the interactive viewer above.