TAMRON SP AF 70-200mm f/2.8 Di LD [IF] MACRO

US 2008/0212200 A1 — Dayong Li, Akio Arakawa

18 ELEMENTS / 13 GROUPS
70-200mm f/2.8 (MARKETING)
71.50-194.00mm F/2.88 (PATENT DESIGN)
0.95 m MFD (CONSTRAINED RECONSTRUCTION)
3 INFERRED LD ELEMENTS

Focus Mechanism

CONSTRAINED_RECONSTRUCTION: G1R (L3-L5) moves 19.124 mm objectward to 0.95 m; D3 decreases and D8 increases by the same amount at each zoom position, preserving the adjacent-gap sum. The patent's printed 9.124 mm value does not reproduce 0.95 m.

Optical Elements (18 physical)

ElementTypeGlass
L1Negative Meniscus786439 coordinate class (vendor unresolved)
L2Biconvex Positive487704 coordinate class (vendor unresolved)
L3Negative Meniscus699301 coordinate class (vendor unresolved)
L4Biconvex Positive487704 coordinate class (vendor unresolved)
L5Biconvex Positive497816 coordinate class (vendor unresolved)
L6Positive Meniscus847238 coordinate class (vendor unresolved)
L7Biconcave Negative640602 coordinate class (vendor unresolved)
L8Biconcave Negative640602 coordinate class (vendor unresolved)
L9Positive Meniscus847238 coordinate class (vendor unresolved)
L10Biconcave Negative786439 coordinate class (vendor unresolved)
L11Biconvex Positive806407 coordinate class (vendor unresolved)
L12Biconvex Positive497816 coordinate class (vendor unresolved)
L13Negative Meniscus847238 coordinate class (vendor unresolved)
L14Positive Meniscus497816 coordinate class (vendor unresolved)
L15Biconcave Negative620363 coordinate class (vendor unresolved)
L16Biconvex Positive834373 coordinate class (vendor unresolved)
L17Negative Meniscus806333 coordinate class (vendor unresolved)
L18Biconvex Positive620363 coordinate class (vendor unresolved)