US 4,258,985 Example 4 — Minolta / Akiyoshi Nakamura
| 9 elements / 9 groups |
| f = 28.0 mm |
| F2.0 |
| 2ω = 75° |
| all-spherical |
Single patent configuration; close focus is represented by unit-extension BFD change to the 0.3 m production MFD.
| Element | Type | Glass |
|---|---|---|
| L1 | Weak Biconvex Positive | 694536 - lanthanum crown (catalog unresolved) |
| L2 | Negative Meniscus | 511605 - crown glass (catalog unresolved) |
| L3 | Negative Meniscus | 511605 - crown glass (catalog unresolved) |
| L4a | Positive Meniscus | 762404 - lanthanum flint class (catalog unresolved) |
| L4b | Weak Biconvex Positive | 762404 - lanthanum flint class (catalog unresolved) |
| L5 | Positive Meniscus | 750504 - dense lanthanum crown class (catalog unresolved) |
| L6 | Biconcave Negative | 805252 - dense flint (catalog unresolved) |
| L7 | Positive Meniscus | 773501 - lanthanum flint (catalog unresolved) |
| L8 | Weak Biconvex Positive | 697558 - lanthanum crown (catalog unresolved) |
Detailed analysis available in the interactive viewer above.