NIKON REFLEX-NIKKOR 500mm f/8 (New)

US 4,666,259 A — Yutaka Iizuka

6 elements / 6 groups
f = 499.482 mm
F/6.7 geometric; f/8 effective
2ω = 5°
all-spherical Mangin catadioptric

Focus Mechanism

Front-unit focus: L1 and M2 move together 8.05 mm toward the object; the rear mirror/corrector block and image plane remain fixed.

Optical Elements (6 physical)

ElementTypeGlass
L1Biconvex PositiveBSC7 / N-BK7 class crown (patent 517/641)
M1Positive Mangin MirrorBSC7 / N-BK7 class crown (patent 517/641)
M2Negative Mangin MirrorBSC7 / N-BK7 class crown (patent 517/641)
L21Near-Plano-Concave NegativeBSC7 / N-BK7 class crown (patent 517/641)
L22Negative MeniscusE-C3 (HOYA) / S-NSL3 class crown (518/590)
L23Positive Meniscus796410 class; NBFD2 catalog spectral proxy (production supplier unspecified)