CN 120386081 A Example 1 - Sigma / Hiromichi Ochiai
| 18 elements / 15 groups |
| 28.84-43.66 mm design EFL |
| F1.8 marketed; F1.86 patent design |
| 75.19°-50.51° patent diagonal field |
| 3 aspherical elements / 6 aspherical surfaces |
| Internal zoom; single negative focus group |
Internal focus by G3 / L6. Patent beta=1/40 spacings are published; close endpoint here is paraxially extrapolated to the official 0.30 m MFD.
| Element | Type | Glass |
|---|---|---|
| L1 | Neg. Meniscus (2x Asph) | L-LAL13 (OHARA) / M-LAC130 class (HOYA, molded lanthanum crown) |
| L2 | Negative Meniscus | S-FPM5 / FCD500 class (low-dispersion fluorophosphate crown) |
| L3 | Biconcave Negative | PCD51 (HOYA) / J-PSKH4 class |
| L4 | Positive Meniscus | FDS18-W (HOYA) / H-ZF88 class |
| L5 | Positive Meniscus | TAC8 (HOYA) / S-LAL18 class |
| L6 | Biconcave Negative | S-LAL21 (OHARA) |
| L7 | Positive Meniscus | TAFD55 (HOYA) / S-LAH99 class |
| L8 | Biconvex Positive (2x Asph) | M-TAFD305 (HOYA, molded high-index glass) |
| L9 | Biconcave Negative | E-FD4L (HOYA) / H-ZF6 class |
| L10 | Biconvex Positive | FCD705 (HOYA) |
| L11 | Biconvex Positive | FCD915 (HOYA) |
| L12 | Biconvex Positive | FCD705 (HOYA) |
| L13 | Biconcave Negative | FDS90-SG/FDS90-SGP (HOYA) / N-SF57HT / S-TIH53W class |
| L14 | Positive Meniscus | FCD515 / FCD505 class (HOYA) |
| L15 | Biconcave Negative | LAF45 (HOYA) / S-NBM51 class |
| L16 | Biconvex Positive | FDS16-W (HOYA) |
| L17 | Biconvex Positive | TAFD32 (HOYA) |
| L18 | Biconcave Negative (2x Asph) | M-NBFD130 (HOYA, molded high-index flint) |
Detailed analysis available in the interactive viewer above.