FUJIFILM FUJINON GF 20-35mm f/4 R WR

US 2022/0236544 A1 Example 10 - FUJIFILM / Nagami

14 elements / 10 groups
f = 20.60-33.99 mm design; 20-35 mm marketed
F/4 nominal; patent FNo. 4.08-4.11
2ω = 110.0°-74.6°
8 aspherical surfaces; 4 ED-class elements

Focus Mechanism

Inner focus by entire G2 (L21-L22). Patent Table 29 gives beta=-0.1 focus spacings at wide and tele; middle close-focus spacing is interpolated for the viewer.

Optical Elements (14)

ElementTypeGlass
L11Negative MeniscusS-NPH3 (OHARA; 959/175 optical match)
L12Neg. Meniscus (2x Asph)MP/MC-BACD12 (HOYA precision-molding class; 583/595)
L13Negative Meniscus EDN-PK52A / FCD1 / S-FPL51 class (497/816 ED)
L14Positive Meniscus Dense FlintS-TIH53-class dense flint (847/238; vendor uncertain)
L21Plano-Convex PositiveTAFD35 (HOYA; 911/353)
L22Weak Neg. Meniscus (2x Asph)E-FD8 (HOYA, 689312 code)
L31Biconvex PositiveN-FK5 / S-FSL5 class (487/704)
L32Biconcave NegativeH-LaF6L / lanthanum flint class (757/477)
L33Plano-Convex EDN-PK52A / FCD1 / S-FPL51 class (497/816 ED)
L34Biconvex Positive ED (2x Asph)Unmatched (ED fluorophosphate, 496/813; near FCD1/S-FPL51 family)
L41Negative Meniscus Dense FlintN-LASF46B / TAFD25 / S-LAH95 class (904/313)
L42Positive Meniscus EDN-PK52A / FCD1 / S-FPL51 class (497/816 ED)
L43Negative Meniscus (2x Asph)MP/MC-LAC130 (HOYA precision-molding class; 694/532)
L51Positive Meniscus Dense Lanthanum FlintTAFD32 / H-ZLaF64 class (871/407)

Analysis

Detailed analysis available in the interactive viewer above.