LEICA SUMMILUX 28mm f/1.7 ASPH. (Leica Q, Q2, Q3)

US 2016/0266350 A1 Example 1 — PANASONIC IPM / IIYAMA & SUEYOSHI

11 ELEMENTS / 9 GROUPS
f ≈ 27.08 mm
F/1.76
2ω ≈ 79.9°
3 ASPHERICAL ELEMENTS (5 SURFACES)

Focus Mechanism

Floating inner focus: G2 (doublet) and G4 (singlet) move toward object. Macro mode (M2) extends G1–G4 as a unit to 0.17 m.

Optical Elements (11)

ElementTypeGlass
L1Biconcave NegativeS-TIL26 (OHARA)
L2Biconvex PositiveS-LAH58 (OHARA)
L3Biconcave NegativeS-TIM5 (OHARA)
L4Biconvex PositiveFCD515 (HOYA)
L5Positive MeniscusTAFD35 (HOYA)
L6Pos. Meniscus (1× Asph)877370 — high-index lanthanum glass (patent nd=1.87722, nu_d=37.0)
L7Negative MeniscusS-TIH14 (OHARA)
L8Biconcave NegativeS-TIH13 (OHARA)
L9Biconvex PositiveS-LAH58 (OHARA)
L10Pos. Meniscus (2× Asph)S-LAH66 (OHARA)
L11Neg. Meniscus (2× Asph)H-ZF52A (CDGM)

Analysis

Detailed analysis available in the interactive viewer above.