PENTAX HD D FA* 85mm f/1.4 ED SDM AW

US 2020/0301101 A1 — Numerical Example 3

12 elements / 10 groups
f = 83.41 mm design; 85 mm marketed
F1.46 design; F1.4 marketed
2ω = 29.0° design; 28.5° marketed
2 aspherical surfaces

Focus Mechanism

Rear focus: the patent states that G1 is fixed and G2 moves toward the object for close focus; no close-focus variable-gap table is published, so this data file carries the verified infinity prescription only.

Optical Elements (12)

ElementTypeGlass
L11Biconcave NegativeS-NBM51 (OHARA)
L12Biconvex PositiveS-FPL53 (OHARA) / FCD100 class
L13Positive MeniscusS-LAH58 (OHARA)
L14Biconvex PositiveS-FPL53 (OHARA) / FCD100 class
L21Positive MeniscusTAFD32 (HOYA, 871/407 lanthanum class)
L22Positive MeniscusS-FPL53 (OHARA) / FCD100 class
L23Negative MeniscusS-NBH52V (OHARA)
L24′Biconcave NegativeS-NBH52V (OHARA)
L25′Biconvex PositiveS-LAH92 (OHARA)
L26′Biconcave NegativeS-NBH53V (OHARA)
L27′Biconvex PositiveS-LAH55V (OHARA)
L28′Biconvex Positive (2× Asph)M-LAC130 / MP-LAC130 (HOYA, moldable lanthanum crown)

Analysis

Detailed analysis available in the interactive viewer above.