JP 2010-101979 A EXAMPLE 5 — SIGMA / OGASAHARA
| 7 ELEMENTS / 6 GROUPS |
| f ≈ 24.1 mm |
| F/2.8 |
| 2ω ≈ 56.8° |
| 2 ASPHERICAL SURFACES |
Rear focus: G2 (L7) translates toward object for close focus, shortening D12 while BF increases. G1 (including stop and doublet G1b) is mechanically fixed.
| Element | Type | Glass |
|---|---|---|
| L1 | Neg. Meniscus (convex front) | S-LAL7 / LACL5 (OHARA / HOYA) |
| L2 | Biconcave Negative | S-TIM5 (≈) (OHARA) |
| L3 | Biconvex Positive | S-LAH55 / TAFD5 (OHARA / HOYA) |
| L4 | Biconvex Positive | N-LASF41A / TaFD30 (Schott / HOYA) |
| L5 | Biconcave Negative | S-TIH family / FD series (OHARA / HOYA) |
| L6 | Biconvex Positive (1× Asph) | S-LAM55 (≈) / LACL60 (OHARA / HOYA) |
| L7 | Pos. Meniscus (1× Asph) | BaCD / SK family (various) |
Detailed analysis available in the interactive viewer above.