US 4,457,596 EMBODIMENT 1 — NIPPON KOGAKU / WAKAMIYA
| 5 ELEMENTS / 4 GROUPS |
| f ≈ 35.0 mm |
| F/2.8 |
| 2ω ≈ 62.3° |
| ALL SPHERICAL |
Unit focus — entire lens translates forward on helicoid; BFD increases by 1.60 mm at 0.8 m.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | LaK 8 (1713/540) |
| L2 | Positive Meniscus | TAF5 (1773/494) |
| L3 | Biconcave Negative | FD60 / S-TIM28 (1689/311) |
| L4 | Biconvex Positive | TAF5 (1773/494) |
| L5 | Negative Meniscus | SK 16 / S-BSM16 (1620/604) |
Detailed analysis available in the interactive viewer above.