JP 2015-41012 A EXAMPLE 1 — TAMRON / SONY
| 7 ELEMENTS / 5 GROUPS |
| f ≈ 36.1 mm |
| F/2.8 |
| 2ω ≈ 62.6° |
| 6 ASPHERICAL SURFACES |
Inner focus — single negative element (L121/G2) moves object→image. Linear AF motor.
| Element | Type | Glass |
|---|---|---|
| L111 | Negative Meniscus | Dense flint, 800/255 class — S-TIH6 (OHARA) or FD60 (Hoya) |
| L112 | Positive Meniscus | S-LAH55V (OHARA) |
| L113 | Biconvex Positive (2× Asph) | Lanthanum flint (LAF class), 760/492 — unresolved; likely PGM-compatible proprietary melt |
| L121 | Negative Meniscus (2× Asph) | L-BAL42 (OHARA) |
| L131 | Biconvex Positive | S-LAH55V (OHARA) |
| L132 | Biconcave Negative | NBFD11 (Hoya) |
| L133 | Negative Meniscus (2× Asph) | S-TIM28 (OHARA) |
Detailed analysis available in the interactive viewer above.