DE 2205380 A1 — Nobuo Yamashita
| 7 ELEMENTS / 7 GROUPS |
| f = 28.007 mm |
| F/3.5 |
| 2ω = 75° |
| ALL-SPHERICAL |
Straight-helicoid unit focus; modeled BF increases from 37.502 mm at infinity to 41.077 mm at 0.30 m.
| Element | Type | Glass |
|---|---|---|
| L1 | Biconvex Positive | S-BAH11 (OHARA current equivalent) |
| L2 | Negative Meniscus | S-BSM16 (OHARA current equivalent) |
| L3 | Biconvex Positive | BAF13 (SUMITA current equivalent) |
| L4 | Positive Meniscus | S-LAL12 (OHARA current equivalent) |
| L5 | Positive Meniscus | J-LAK8 (HIKARI current equivalent) |
| L6 | Biconcave Negative | S-TIH13 (OHARA current equivalent) |
| L7 | Plano-Convex Positive | J-LAK8 (HIKARI current equivalent) |