US 8,736,971 B2 Numerical Example 3 — Canon / Hatada
| 18 elements / 13 groups |
| 24-70 mm f/2.8 marketed; 24.70-67.88 mm F/2.91 patent design |
| 3 aspherical elements / 4 aspherical surfaces |
| 1 Super UD + 2 UD-class ED elements |
| Inner focus: second lens unit |
Inner focusing by moving the complete second lens unit. Close-focus spacings are paraxially inferred from Canon's 0.38 m MFD; the patent itself publishes infinity-focus zoom spacings only.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | S-TIH53 (OHARA; dense flint) |
| L2 | Positive Meniscus | S-LAH66 (OHARA; high-index lanthanum flint, code 773/496) |
| L3 | Positive Meniscus | S-LAH66 (OHARA; high-index lanthanum flint, code 773/496) |
| L4 | Neg. Meniscus (1× Asph) | S-LAH58 (OHARA; equivalent to HOYA TAFD30, dense lanthanum flint) |
| L5 | Biconcave Negative | S-FPM2 (OHARA; fluorophosphate crown / HOYA FCD515 class) |
| L6 | Positive Meniscus | S-LAH58 (OHARA; equivalent to HOYA TAFD30, dense lanthanum flint) |
| L7 | Biconvex Positive | S-FTM16 (OHARA; titanium flint, code 593353) |
| L8 | Biconcave Negative | S-LAL18 (OHARA; lanthanum crown) |
| L9 | Biconvex Positive | S-TIH53 (OHARA; dense flint) |
| L10 | Negative Meniscus | S-LAH58 (OHARA; dense lanthanum flint) |
| L11 | Biconvex Positive | S-FPL51 (OHARA; UD-class ED fluorophosphate) |
| L12 | Positive Meniscus (1× Asph) | S-BAL42 (OHARA; barium crown) |
| L13 | Negative Meniscus | N-KZFS8 (Schott; S-NBH8-equivalent KZFS-family glass, code 720347) |
| L14 | Biconvex Positive | S-FPL53 (OHARA; Super UD-class ED fluorophosphate) |
| L15 | Biconvex Positive | S-FPL51 (OHARA; UD-class ED fluorophosphate) |
| L16 | Biconcave Negative (2× Asph) | M-TAFD305-class moldable glass (HOYA; patent 850/402, catalog family 851/401) |
| L17 | Biconcave Negative | S-LAH60 (OHARA; dense lanthanum flint) |
| L18 | Biconvex Positive | S-BSL7 (OHARA; N-BK7 equivalent borosilicate crown) |
Detailed analysis available in the interactive viewer above.