US 4,871,239 Example 3 / Claim 29
| 35-105 mm full-frame A-mount zoom |
| Patent f = 36.0-60.0-102.0 mm |
| 13 optical media / 10 groups (12 production elements) |
| 1 rear-unit aspherical surface |
| 0.85 m minimum focus distance |
Rear-group focusing by Group III-F and Group III-B. The patent gives no close-focus spacing table for Example 3, so the model represents the verified infinity-focus zoom positions only.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | SF57 (Schott exact match; production vendor unproven) |
| L2 | Biconvex Positive | 670571 - high-index crown / lanthanum-crown class (unresolved) |
| L3 | Positive Meniscus | H-LAK12 (CDGM equivalent; patent 697565) |
| L4 | Negative Meniscus | 773498 - dense lanthanum-flint boundary class (unresolved) |
| L5 | Plano-Concave Negative | 670571 - high-index crown / lanthanum-crown class (unresolved) |
| L6 | Positive Meniscus | SF57 (Schott exact match; production vendor unproven) |
| L7 | Biconcave Negative | N-PSK53A (Schott exact match; production vendor unproven) |
| L8 | Biconvex Positive | 670571 - high-index crown / lanthanum-crown class (unresolved) |
| L9 | Biconvex Positive | N-BK7 / BK7-family crown (517/642 class) |
| L10 | Biconcave Negative | 807316 - high-index dense flint class (unresolved) |
| L11 | Biconvex Positive | S-LAM58 (OHARA) |
| L12 | Thin Aspheric Layer | 518523 - thin hybrid aspheric layer (unresolved) |
| L13 | Negative Meniscus | 805410 - dense lanthanum-flint / LASF-class glass (unresolved) |
Detailed analysis available in the interactive viewer above.