JP 2010-044103 A — Akio Arakawa, Yuichi Muramatsu
| 18 ELEMENTS / 13 GROUPS |
| DESIGN f = 18.40–264.21 mm |
| DESIGN F/3.50–6.32 |
| 3 ASPHERICAL SURFACES / 3 ELEMENTS |
| INNER FOCUS / VC |
Infinity focus only. The patent focuses by moving the second group (LG2) toward the object, but it prints no near-focus spacings, so no focus movement is modeled: every zoom state stays at infinity focus. The 0.49 m end of the focus scale is Tamron's marketed minimum focus distance and does not move any group.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | 847238 - dense-flint class |
| L2 | Biconvex Positive | 497816 - fluor-crown class (LD) |
| L3 | Positive Meniscus | 618634 - phosphate-crown class (AD) |
| L4r | Hybrid Resin Layer (1× Asph) | Unmatched (hybrid asphere resin/polymer, nd=1.51460, vd=49.96) |
| L4g | Negative Meniscus | 804466 - lanthanum-flint class |
| L5 | Biconcave Negative | 804466 - lanthanum-flint class |
| L6 | Biconvex Positive | 847238 - dense-flint class |
| L7 | Negative Meniscus | 883408 - high-index lanthanum-flint class |
| L8 | Negative Meniscus | 847238 - dense-flint class |
| L9 | Biconvex Positive | 487702 - fluor-crown class |
| L10 | Biconvex Positive | 487702 - fluor-crown class |
| L11 | Positive Meniscus | 497816 - fluor-crown class (LD) |
| L12 | Negative Meniscus | 834372 - lanthanum-flint class |
| L13r | Hybrid Resin Layer (1× Asph) | Unmatched (hybrid asphere resin/polymer, nd=1.53610, vd=41.20) |
| L13g | Biconcave Negative | 772496 - lanthanum-flint class |
| L14 | Positive Meniscus | 808228 - dense-flint class |
| L15r | Hybrid Resin Layer (1× Asph) | Unmatched (hybrid asphere resin/polymer, nd=1.51460, vd=49.96) |
| L15g | Biconvex Positive | 487702 - fluor-crown class |
| L16 | Biconvex Positive | 487702 - fluor-crown class |
| L17 | Biconcave Negative | 804466 - lanthanum-flint class |
| L18 | Biconvex Positive | 487702 - fluor-crown class |