MINOLTA AF Reflex 500mm f/8

US 4,951,078 — Takashi Okada

500 mm f/8 fixed
f = 495.97 mm patent EFL
f/7.07 area-equivalent annular design aperture
5 groups / 7 elements incl. plug-in filter
All-spherical catadioptric Cassegrain

Focus Mechanism

Production lens minimum focus is 4.0 m. US 4,951,078 publishes only the infinity prescription, so close-focus optical spacings are not modeled.

Optical Elements (7 physical)

ElementTypeGlass
L1Positive MeniscusBSC7 / N-BK7 class (517/642)
M1Annular Mangin Primary MirrorS-LAL52 (OHARA catalog-equivalent to 670571; patent vendor unspecified)
M2Mangin Secondary MirrorBSC7 / N-BK7 class (517/642)
L3Positive MeniscusLAC8 / N-LAK8 class (713/539)
L4Negative MeniscusBSC7 / N-BK7 class (517/642)
L5Nearly Afocal MeniscusS-LAL52 (OHARA catalog-equivalent to 670571; patent vendor unspecified)
L6Negative MeniscusS-LAL52 (OHARA catalog-equivalent to 670571; patent vendor unspecified)