RICOH LENS A16 24-85mm F3.5-5.5 — Optical Cross-Section & Ray Tracing

Home / Lenses / Ricoh / RICOH LENS A16 24-85mm F3.5-5.5RICOH LENS A16 24-85mm F3.5-5.5US 2012/0307375 A1↗ — Yohei Takano, Hiromichi Atsuumi
11 ELEMENTS / 9 GROUPS
15.7-55.5 mm actual (24-85 mm equivalent)
f/3.5-5.5 marketed; f/3.62-5.67 patent design
6 ASPHERICAL SURFACES
Focus MechanismCONSTRAINED_RECONSTRUCTION: only Group III (L6) moves. Close-focus spacings are paraxially solved for a 0.25 m object distance from patent surface 1 with a fixed normalized image plane and exact B+C conservation; Ricoh's marketed 0.25 m MFD is measured from the physical lens front, so this is not a patent-published finite-focus state.
Optical Elements (11 physical)ElementTypeGlass
L1Negative Meniscus847238 class
L2Positive Meniscus773496 class
L3Negative Meniscus001291 class
L4Biconcave Negative (2× Asph)L-LAH87 (OHARA)
L5Biconvex Positive847238 class
L6Negative MeniscusS-BSM71 (OHARA)
L7Biconvex Positive (2× Asph)516641 class
L8Biconvex Positive517524 class
L9Biconcave Negative834372 class
L10Biconvex Positive (2× Asph)589612 class
L11Negative Meniscus904313 class

Element	Type	Glass
L1	Negative Meniscus	847238 class
L2	Positive Meniscus	773496 class
L3	Negative Meniscus	001291 class
L4	Biconcave Negative (2× Asph)	L-LAH87 (OHARA)
L5	Biconvex Positive	847238 class
L6	Negative Meniscus	S-BSM71 (OHARA)
L7	Biconvex Positive (2× Asph)	516641 class
L8	Biconvex Positive	517524 class
L9	Biconcave Negative	834372 class
L10	Biconvex Positive (2× Asph)	589612 class
L11	Negative Meniscus	904313 class