US 4,487,485 Example 1 — Asahi / Hisada
| 45mm f/2.8 |
| 9 elements / 8 groups |
| 76° on 645 film |
| All-spherical |
| Unit focus |
Unit focus. The patent gives only the infinity prescription; close focus is modeled by increasing the final back-focus gap from 62.0115 mm to 68.4912 mm, matching a 0.45 m object-to-image distance in a thick-lens paraxial solve.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | S-BAL35 (OHARA) |
| L2 | Negative Meniscus | S-FSL5 (OHARA) |
| L3 | Negative Meniscus | S-FSL5 (OHARA) |
| L4 | Near Plano-Convex Positive | S-LAM52 (OHARA) |
| L5 | Biconvex Positive | S-LAM52 (OHARA) |
| L6 | Biconcave Negative | S-TIH6 (OHARA) |
| L7 | Positive Meniscus | S-LAH55V (OHARA) |
| L8 | Near Plano-Concave Negative | S-TIH6 (OHARA) |
| L9 | Biconvex Positive | S-LAH65V (OHARA) |
Detailed analysis available in the interactive viewer above.