CANON EF-M 15-45mm f/3.5-6.3 IS STM — Optical Cross-Section & Ray Tracing

Home / Lenses / Canon / CANON EF-M 15-45mm f/3.5-6.3 IS STMCANON EF-M 15-45mm f/3.5-6.3 IS STMJP 2016-118658 A↗, Numerical Example 8 — Taku Inoue
10 ELEMENTS / 9 GROUPS
MARKETED 15-45mm f/3.5-6.3
PATENT 15.45-44.45mm f/3.58-6.44
3 ASPHERICAL ELEMENTS / 6 ASPHERICAL SURFACES
0.25 m MFD / 0.25× AT 45mm
OPTICAL IS / LEAD-SCREW STM / RETRACTING BARREL
Focus MechanismCONSTRAINED_RECONSTRUCTION: L3 alone translates imageward for near focus. The patent publishes no finite-focus spacing table. Close s14/s16 rows are code-solved at each zoom station to Canon's 0.25 m MFD while s14+s16 = 7.72 mm. The tele close state gives paraxial |m|≈0.253, consistent with Canon's rounded 0.25× claim.
Optical Elements (10 physical)ElementTypeGlass
E1Negative Meniscus804466 — high-index lanthanum glass class (vendor unresolved)
E2Neg. Meniscus (2× Asph)Unmatched (nd=1.52996, nu_d=55.8; no exact defensible public-catalog identity found)
E3Positive Meniscus923189 — very-high-index flint class (vendor unresolved)
E4Biconvex Positive487702 — low-dispersion crown class (vendor unresolved)
E5Biconvex PositiveS-LAL13 (coordinate-compatible spectral proxy; production supplier unspecified)
E6Biconcave Negative847239 — dense flint class (vendor unresolved)
E7Biconvex Positive (2× Asph)583594 — crown class (vendor unresolved)
E8Negative Meniscus904313 — high-index lanthanum flint class (vendor unresolved)
E9Negative Meniscus (2× Asph)Unmatched (nd=1.52996, nu_d=55.8; no exact defensible public-catalog identity found)
E10Positive Meniscus614550 — crown class (historical OHARA S-BSM9 coordinate match; vendor unresolved)

Element	Type	Glass
E1	Negative Meniscus	804466 — high-index lanthanum glass class (vendor unresolved)
E2	Neg. Meniscus (2× Asph)	Unmatched (nd=1.52996, nu_d=55.8; no exact defensible public-catalog identity found)
E3	Positive Meniscus	923189 — very-high-index flint class (vendor unresolved)
E4	Biconvex Positive	487702 — low-dispersion crown class (vendor unresolved)
E5	Biconvex Positive	S-LAL13 (coordinate-compatible spectral proxy; production supplier unspecified)
E6	Biconcave Negative	847239 — dense flint class (vendor unresolved)
E7	Biconvex Positive (2× Asph)	583594 — crown class (vendor unresolved)
E8	Negative Meniscus	904313 — high-index lanthanum flint class (vendor unresolved)
E9	Negative Meniscus (2× Asph)	Unmatched (nd=1.52996, nu_d=55.8; no exact defensible public-catalog identity found)
E10	Positive Meniscus	614550 — crown class (historical OHARA S-BSM9 coordinate match; vendor unresolved)