CANON EF-M 11-22mm f/4-5.6 IS STM

US 2014/0098253 A1 — Satoshi Maetaki

12 ELEMENTS / 9 GROUPS
11-22mm f/4-5.6 MARKETED
11.0037-22.0132mm COMPUTED DESIGN
2 ASPHERICAL ELEMENTS / 3 ASPHERICAL SURFACES
LATERAL IS UNIT / REAR FOCUS
CONSTRAINED 0.15m FOCUS RECONSTRUCTION

Focus Mechanism

CONSTRAINED_RECONSTRUCTION: patent infinity zoom states retained; only U3 (authored L10; surfaces 18-19) translates for focus. At Canon's 0.15 m focal-plane-to-subject MFD, code-solved U3 imageward travel is 1.449509 / 2.180303 / 3.466319 mm at 11 / 15.5 / 22 mm, with D17 + D19 = 7.08 mm conserved. Close spacings are modeled, not patent-published.

Optical Elements (12 physical)

ElementTypeGlass
L1Neg. Meniscus (2× Asph)583594 crown class (vendor unresolved)
L2Biconcave Negative773496 lanthanum-flint class (vendor unresolved)
L3Biconvex Positive911353 high-index lanthanum-flint class (vendor unresolved)
L4Positive Meniscus697555 lanthanum-crown class (vendor unresolved)
L5Biconvex Positive517524 crown class (vendor unresolved)
L6Biconcave Negative883408 lanthanum-dense-flint class (vendor unresolved)
L7Biconvex Positive532488 light-flint class (vendor unresolved)
L8Biconvex Positive497815 high-Abbe ED/UD class (vendor unresolved)
L9Neg. Meniscus (1× Asph)854404 low-Tg lanthanum class (vendor unresolved)
L10Negative Meniscus834372 lanthanum-flint class (vendor unresolved)
L11Biconvex Positive626357 flint class (vendor unresolved)
L12Negative Meniscus835427 lanthanum-dense-flint class (vendor unresolved)