MINOLTA RF 250mm f/5.6 — Optical Cross-Section & Ray Tracing

Home / Lenses / Minolta / MINOLTA RF 250mm f/5.6MINOLTA RF 250mm f/5.6US 4,264,136 A↗ — Shuji Ogino
5 PHYSICAL ELEMENTS / 4 GROUPS
2 SECOND-SURFACE MIRRORS
EXAMPLE 2 DESIGN f/4.5; MARKETED f/5.6
Focus MechanismNO_INTERNAL_RECONSTRUCTION: the fixed prescription uses a calculated paraxial image plane. The patent places actual useful focus behind this plane without a numerical offset. The 2.5 m close-focus value is manufacturer metadata; no internal movement or finite-focus optical result is claimed.
Optical Elements (5 physical; 6 modeled media)ElementTypeGlass
L1Positive MeniscusS-NSL36 spectral proxy (OHARA; light crown; patent vd 53.5 retained versus catalog 52.43; supplier unconfirmed)
M2Positive Meniscus Second-Surface MirrorN-BK7 spectral proxy (Schott; borosilicate crown; production supplier unconfirmed)
M1Negative Meniscus Second-Surface MirrorN-BK7 spectral proxy (Schott; borosilicate crown; production supplier unconfirmed)
L3Clear Central Primary PlugN-BK7 spectral proxy (Schott; borosilicate crown; production supplier unconfirmed)
L4Biconcave NegativeN-BK7 spectral proxy (Schott; borosilicate crown; production supplier unconfirmed)
L5Biconvex PositiveS-TIH3 spectral proxy (OHARA; dense flint; production supplier unconfirmed)

Element	Type	Glass
L1	Positive Meniscus	S-NSL36 spectral proxy (OHARA; light crown; patent vd 53.5 retained versus catalog 52.43; supplier unconfirmed)
M2	Positive Meniscus Second-Surface Mirror	N-BK7 spectral proxy (Schott; borosilicate crown; production supplier unconfirmed)
M1	Negative Meniscus Second-Surface Mirror	N-BK7 spectral proxy (Schott; borosilicate crown; production supplier unconfirmed)
L3	Clear Central Primary Plug	N-BK7 spectral proxy (Schott; borosilicate crown; production supplier unconfirmed)
L4	Biconcave Negative	N-BK7 spectral proxy (Schott; borosilicate crown; production supplier unconfirmed)
L5	Biconvex Positive	S-TIH3 spectral proxy (OHARA; dense flint; production supplier unconfirmed)