CANON EF 50mm f/1.0 L USM

US 4,717,245, Numerical Example 2 — Sadatoshi Takahashi

11 ELEMENTS / 9 GROUPS
f ≈ 50.0 mm
F/1.0
2ω ≈ 45.2°
2 ASPHERICAL SURFACES

Focus Mechanism

CONSTRAINED_RECONSTRUCTION: unit extension of the whole optical block follows the source preferred mechanism; the existing close-focus back gap is calculated for the correlated 0.6 m endpoint. The original supplies no finite table or production floating-group displacements, and linear intermediate motion is approximate.

Optical Elements (11 physical)

ElementTypeGlass
L1Positive MeniscusBACD14 (spectral proxy; d-line inferred from printed coordinates; supplier, melt and chemistry unspecified)
L2Positive MeniscusS-LAL14 (spectral proxy; d-line inferred from printed coordinates; supplier, melt and chemistry unspecified)
L3Neg. Meniscus (1× Asph)S-NSL36 (spectral proxy; d-line inferred from printed coordinates; supplier, melt and chemistry unspecified)
L4Positive MeniscusS-LAH58 (spectral proxy; d-line inferred from printed coordinates; supplier, melt and chemistry unspecified)
L5Negative MeniscusS-NSL36 (spectral proxy; d-line inferred from printed coordinates; supplier, melt and chemistry unspecified)
L6Biconcave NegativePBH53 (spectral proxy; d-line inferred from printed coordinates; supplier, melt and chemistry unspecified)
L7Biconvex PositiveS-LAH58 (spectral proxy; d-line inferred from printed coordinates; supplier, melt and chemistry unspecified)
L8Neg. Meniscus (1× Asph)SF6 (spectral proxy; d-line inferred from printed coordinates; supplier, melt and chemistry unspecified)
L9Positive MeniscusS-LAH58 (spectral proxy; d-line inferred from printed coordinates; supplier, melt and chemistry unspecified)
L10Biconvex PositiveS-LAH58 (spectral proxy; d-line inferred from printed coordinates; supplier, melt and chemistry unspecified)
L11Positive MeniscusS-BAL50 (spectral proxy; d-line inferred from printed coordinates; supplier, melt and chemistry unspecified)