KR 10-1918210 B1 — Jae Myung Yu, Hae Jin Lee, Jung Du Lee
| 15 ELEMENTS / 10 GROUPS |
| DESIGN f = 14.19 mm |
| DESIGN F/2.85 |
| 4 ASPHERICAL SURFACES / 2 ELEMENTS |
| THREE PUBLISHED FOCUS STATES |
PUBLISHED: the cemented triplet L83–L103 (group G23) moves 3.23 mm toward the object between the patent's three tabulated states — infinity, magnification 0.033, and magnification 0.157 at 0.20 m object-to-image, which is also Samyang's stated minimum focus distance. The D1/D2 gaps at those states are the printed values; gaps between them are interpolated. G13 and G33 stay fixed. The image plane is placed 0.5 mm behind the cover plate, the sum of the patent's printed D4 and D5 at each focus state. The iris is held at its infinity setting, so the model does not reproduce the patent's near-state F-number of 2.938.
| Element | Type | Glass |
|---|---|---|
| L13 | Positive Meniscus | NBFD15 (Hoya equivalent) |
| L23 | Negative Meniscus | TAC8 (Hoya equivalent) |
| L33 | Negative Meniscus | TAF3 (Hoya equivalent) |
| L43 | Neg. Meniscus (2× Asph) | Unmatched (lanthanum crown class; source 1.77271 / 49.70) |
| L53 | Biconcave Negative | E-FDS1 (Hoya equivalent) |
| L63 | Biconvex Positive | E-FD13 (Hoya equivalent) |
| L73 | Biconvex Positive | FDS90 (Hoya equivalent) |
| L83 | Negative Meniscus | LAC14 (Hoya equivalent) |
| L93 | Biconvex Positive | E-C3 (Hoya equivalent) |
| L103 | Negative Meniscus | E-FDS1 (Hoya equivalent) |
| L113 | Biconcave Negative | TAFD45 (Hoya equivalent) |
| L123 | Biconvex Positive | FD110 (Hoya equivalent) |
| L133 | Biconvex Positive (2× Asph) | Unmatched (low-dispersion crown class; source 1.55352 / 71.5) |
| L143 | Negative Meniscus | TAFD45 (Hoya equivalent) |
| L153 | Biconvex Positive | FCD1 (Hoya equivalent) |