NIKON NIKKOR Z 50mm f/1.8 S

Patent WO2019/220618 A1 — Example 9

12 elements / 9 groups
EFL 51.6 mm
f/1.85
2ω = 45.8°
2 Asph · 2 ED
MFD 0.4 m

Focus Mechanism

Inner focus — G2 (L21 + L22 + L23) translates 7.9 mm toward the object. G1 and G3 remain fixed. Stepping motor (STM) drive.

Optical Elements (12)

ElementTypeGlass
L11Biconcave NegativeS-TIM25 class (dense flint; patent nd=1.67270, νd=32.2)
L12Pos. Meniscus (convex to obj.)946180 — ultra-high-index short flint (proprietary, patent nd=1.94595, νd=18.0)
L13Pos. Meniscus (concave to obj.)S-LAL18 class (lanthanum crown)
L14Pos. Meniscus (Asph, convex to obj.)S-LAH65V class (lanthanum dense flint, nd = 1.804)
L15Biconvex Positive (ED)S-FPM2 / FCD505 class (ED fluorophosphate; patent nd=1.59319, νd=67.9)
L16Biconcave NegativeS-TIM22 class (dense flint; patent nd=1.64769, νd=33.7)
L21Biconcave NegativeS-TIM22 class (dense flint; patent nd=1.64769, νd=33.7)
L22Biconvex Positive (2× Asph)774472 — lanthanum dense flint (proprietary, patent nd=1.77377, νd=47.2)
L23Pos. Meniscus (concave to obj., ED)S-FPL51 / FCD1 class (ED fluorophosphate, νd = 82.6)
L31Pos. Meniscus (concave to obj.)946180 — ultra-high-index short flint (proprietary, patent nd=1.94595, νd=18.0)
L32Neg. Meniscus (concave to obj.)S-TIM22 class (dense flint; patent nd=1.64769, νd=33.7)
L33Concave-Plano NegativeS-TIM22 class (dense flint; patent nd=1.64769, νd=33.7)

Analysis

Detailed analysis available in the interactive viewer above.