CANON EF 24mm f/1.4 L USM

JP 1999-030743 A — Makoto Misaka

11 ELEMENTS / 9 GROUPS
PATENT f = 24.6 mm, F/1.45, 2ω = 82.7°
1 UD ELEMENT / 1 GROUND ASPHERICAL ELEMENT
FLOATING REAR FOCUS (PRODUCTION)

Focus Mechanism

Production floating rear focus. Patent ¶0039 prefers fixed B1 with B2a and B2b moving objectward while approaching one another; finite-focus spacings are not published and are not modeled.

Optical Elements (11 physical)

ElementTypeGlass
L1Negative Meniscus, convex to objectS-LAL14 (OHARA; 697/555 class equivalent)
L2Negative Meniscus, convex to objectS-LAL14 (OHARA; 697/555 class equivalent)
L3Biconvex PositiveN-LAK8 (SCHOTT; 713/538 class equivalent)
L4Positive Meniscus, convex to objectS-TIH53 (OHARA; 847/238 dense-flint class equivalent)
L5Negative Meniscus, convex to objectS-FPL51 (OHARA; 497/816 fluorophosphate ED class)
L6Biconvex PositiveS-LAH65V (OHARA; 804/466 dense lanthanum-flint class equivalent)
L7Biconcave NegativeS-TIH10 (OHARA; corrected 728/285 dense-flint class)
L8Biconcave NegativeS-TIH6 (OHARA; 805/254 SF6-class equivalent)
L9Biconvex Positive (1× Asph)S-LAH55V (OHARA; 835/427 dense lanthanum-flint class equivalent)
L10Positive Meniscus, convex to imageS-BSM14 (OHARA; J-SK14 603/607 class; patent nd emended)
L11Positive Meniscus, convex to imageS-LAH66N (OHARA; 773/496 lanthanum-flint class equivalent)