JP S55-560 A, Example 1 — Ryoichi Doi, Soho Takahashi
| 4 ELEMENTS / 4 GROUPS |
| 85 mm MARKETED; 89.814 mm TRACED DESIGN |
| f/4 MARKETED; f/2.8 PATENT EXAMPLE |
| 2ω = 28° (PATENT) |
| ALL-SPHERICAL |
Infinity prescription only. Example 1 publishes no focus spacing schedule. The manufacturer’s 1.0 m minimum focus distance is shown for reference; internal travel is not modeled.
| Element | Type | Glass |
|---|---|---|
| G1 | Positive Meniscus | 603607 — SK14/BSM14/BACD14-class crown (vendor unresolved) |
| G2 | Positive Meniscus | 603607 — SK14/BSM14/BACD14-class crown (vendor unresolved) |
| G3 | Negative Meniscus | 762265 — SF14/TIH14/SFLD14-class dense flint (vendor unresolved) |
| G4 | Positive Meniscus | 603607 — SK14/BSM14/BACD14-class crown (vendor unresolved) |