CANON RF 70-200mm f/2.8 L IS USM

JP2021-056407A EXAMPLE 3 — CANON / NAKAHARA, IWAMOTO

17 ELEMENTS / 7 ZOOM GROUPS
f = 72.13–194.06 mm
F/2.89–2.91
2ω = 33.4–12.7°
2 ASPHERICAL SURFACES (GMo)

Focus Mechanism

Dual Nano USM electronic floating focus. Group A (LN/G6, single element L15): moves image-ward for infinity→close. Group B (LR/G7, L16+L17): independent floating correction driven by second Nano USM. Close-focus gap data not available from patent — zoom-only variable gaps used as placeholder.

Optical Elements (17)

ElementTypeGlass
L1Positive MeniscusS-FPL51 (OHARA)
L2Negative MeniscusN-KZFS4 / S-NBM51 class (613443)
L3Plano-Convex PositiveS-FPL55 (OHARA)
L4Biconcave NegativeS-FPM2 (OHARA)
L5Biconcave Negative764485 - M-TAFD305 / high-index lanthanum
L6Positive MeniscusS-NBH56 (OHARA)
L7Biconvex Positive (1× Asph)S-FPL51 (OHARA)
L8Biconcave Negative593353 - S-FTM16 / titanium flint
L9Biconvex Positive728285 - dense flint
L10Negative Meniscus051269 - ultra-high-index dense flint
L11Biconvex PositiveS-FPL51 (OHARA)
L12Biconvex PositiveS-FPL51 (OHARA)
L13Negative Meniscus051269 - ultra-high-index dense flint
L14Biconvex PositiveTAFD37A (HOYA)
L15Negative MeniscusS-PHM52 (OHARA)
L16Positive MeniscusS-NBH56 (OHARA)
L17Neg. Meniscus (1× Asph)S-BAL42 (OHARA)

Analysis

Detailed analysis available in the interactive viewer above.