US 5,438,455 A — Masahiro Nakashima
| 10 ELEMENTS / 7 GROUPS |
| 400mm f/2.8 MARKETED |
| 392.0066 mm PATENT F |
| INTERNAL FOCUS — PUBLISHED G2 MOTION |
| ALL-SPHERICAL |
PUBLISHED internal focus: negative unit G2 translates 17.8317 mm imageward from infinity to the patent R=3.300 m endpoint; d9 expands 8.2485→26.0802 mm while d14 contracts 23.0326→5.2009 mm, preserving d9+d14=31.2811 mm. No reconstructed focus state is used.
| Element | Type | Glass |
|---|---|---|
| L11 | Biconvex Positive | J-FKH1 (HIKARI catalog correlation; patent vendor unspecified) |
| L12 | Biconvex Positive | J-FKH1 (HIKARI catalog correlation; patent vendor unspecified) |
| L13 | Biconcave Negative | J-LAF7 (HIKARI catalog correlation; patent vendor unspecified) |
| L14a | Negative Meniscus | J-LAK14 (HIKARI catalog correlation; patent vendor unspecified) |
| L14b | Positive Meniscus | J-PSKH1 (HIKARI catalog correlation; patent vendor unspecified) |
| L21 | Biconcave Negative | J-BK7A (HIKARI catalog correlation; patent vendor unspecified) |
| L22a | Positive Meniscus | J-SF03 (HIKARI catalog correlation; patent vendor unspecified) |
| L22b | Biconcave Negative | J-LLF6 (HIKARI line-data correlation; patent νd differs by +0.32) |
| L3a | Biconvex Positive | J-FKH1 (HIKARI catalog correlation; patent vendor unspecified) |
| L3b | Negative Meniscus | J-SF8 (HIKARI catalog correlation; patent vendor unspecified) |