CANON EF-S 18-200mm f/3.5-5.6 IS

JP 2009-175324 A, Numerical Example 1 — Makoto Misaka

16 ELEMENTS / 12 GROUPS
DESIGN f = 18.60–193.23 mm
DESIGN F/3.60–5.88
2 ASPHERICAL SURFACES / 2 ELEMENTS
2 UD ELEMENTS

Focus Mechanism

Inner focus. The patent prints infinity spacings only and prefers focusing by moving the negative group L2 (E4–E7) toward the object (¶0082). Here L2 moves that way, D5 shorter and D13 longer by the same amount, with the image plane fixed; the travel to Canon's 0.45 m minimum focus is 0.92 mm at 18.6 mm, 2.07 mm at 49.94 mm and 8.90 mm at 193.23 mm. These finite spacings are derived, not printed. The zoom positions between the three printed focal lengths follow a derived cam (Gpf and Gpr move together, as ¶0039 describes), not Canon's factory cam.

Optical Elements (16 physical)

ElementTypeGlass
E1Meniscus NegativeNBFD15 (HOYA catalog equivalent; production supplier unspecified)
E2Biconvex PositiveS-FPL51 (OHARA catalog equivalent; production supplier unspecified)
E3Meniscus PositiveS-BSM14 (OHARA catalog equivalent; production supplier unspecified)
E4Meniscus NegativeS-LAH55V (OHARA catalog equivalent; production supplier unspecified)
E5Biconcave NegativeS-LAH66 (OHARA catalog equivalent; production supplier unspecified)
E6Biconvex PositiveS-TIH6 (OHARA catalog equivalent; production supplier unspecified)
E7Biconcave NegativeS-LAH66 (OHARA catalog equivalent; production supplier unspecified)
E8Biconvex Positive (Asph)L-BAL42 (OHARA catalog equivalent; production supplier unspecified)
E9Meniscus NegativeS-TIH6 (OHARA catalog equivalent; production supplier unspecified)
E10Biconvex PositiveS-FSL5 (OHARA catalog equivalent; production supplier unspecified)
E11Biconcave NegativeS-LAL8 (OHARA catalog equivalent; production supplier unspecified)
E12Meniscus PositiveNBFD15 (HOYA catalog equivalent; production supplier unspecified)
E13Meniscus NegativeS-LAH55V (OHARA catalog equivalent; production supplier unspecified)
E14Biconvex PositiveS-FPL51 (OHARA catalog equivalent; production supplier unspecified)
E15Biconvex Positive (Asph)L-BAL42 (OHARA catalog equivalent; production supplier unspecified)
E16Meniscus NegativeS-LAH55V (OHARA catalog equivalent; production supplier unspecified)