JP 2013-186458 A — Numerical Example 3
| 17mm f/1.8 |
| Patent f = 17.30 mm / FNO = 1.716 |
| 9 elements / 6 groups |
| 5 aspherical surfaces |
| Inner focus by G2 translation |
Inner focus: G2 (L6+L7 and L8) translates object-ward; G1, aperture stop, and G3 remain fixed.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus (2× Asph) | L-BAL42 (OHARA low-Tg family; patent nd=1.58313) |
| L2 | Biconcave Negative | S-TIL26 (OHARA) |
| L3 | Biconvex Positive | TAFD35L (HOYA) |
| L4 | Biconvex Positive | S-LAH59 (OHARA) |
| L5 | Negative Meniscus | FF8 (HOYA fluor flint) |
| L6 | Biconcave Negative | S-TIM28 (OHARA) |
| L7 | Biconvex Positive (1× Asph) | L-BAL42 (OHARA low-Tg family; patent nd=1.58313) |
| L8 | Biconvex Positive (2× Asph) | S-LAM60 (OHARA; low-Tg L-LAM60 family is adjacent) |
| L9 | Negative Meniscus | S-FTM16 (OHARA) |
Detailed analysis available in the interactive viewer above.