US 4,437,734 A — Yutaka Iizuka
| 9 ELEMENTS / 6 GROUPS |
| 120mm f/4 (MARKETING) |
| f = 121.168 mm (DESIGN) |
| 43.28 mm IMAGE CIRCLE |
| INTERNAL FOCUS TO 1:1 |
PUBLISHED — G2 alone translates 30.242 mm toward the image from infinity to the patent -1.002x state; G1, G3, the diaphragm-to-G3 spacing, and the 58.798 mm back focus remain fixed. The published -0.504x intermediate state lies on the same linear translation.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | 805255 — dense-flint class (vendor unresolved) |
| L2 | Biconvex Positive | 713539 — lanthanum-crown class (vendor unresolved) |
| L3 | Biconvex Positive | 713539 — lanthanum-crown class (vendor unresolved) |
| L4 | Positive Meniscus | 785261 — SF56A catalog equivalent (production supplier unspecified) |
| L5 | Biconcave Negative | 697556 — K-LaK14 catalog equivalent (production supplier unspecified) |
| L6 | Positive Meniscus | 713539 — lanthanum-crown class (vendor unresolved) |
| L7 | Negative Meniscus | 723380 — S-BAH28 catalog equivalent (production supplier unspecified) |
| L8 | Negative Meniscus | 785261 — SF56A catalog equivalent (production supplier unspecified) |
| L9 | Biconvex Positive | N-SK10 catalog equivalent for 1.62280/56.7 (production supplier unspecified) |