RICOH GR LENS A12 28mm f/2.5 — Interactive Lens Diagram

Home / Lenses / Ricoh / RICOH GR LENS A12 28mm f/2.5RICOH GR LENS A12 28mm f/2.5JP 2012-003015 A EXAMPLE 3 — KUBOTA / RICOH
8 ELEMENTS / 6 GROUPS
f = 18.28 mm (28 mm equiv.)
F/2.56
2ω ≈ 75.6°
3 ASPHERICAL SURFACES
Focus MechanismFloating focus — both groups advance independently toward the object at different rates.
Optical Elements (8)ElementTypeGlass
L1Neg. Meniscus (2× Asph)S-BSL7 (OHARA) / N-BK7 (SCHOTT)
L2Positive MeniscusS-LAH58 (OHARA)
L3Biconcave NegativeS-TIM2 (OHARA) / N-F2 (SCHOTT)
L4Biconvex PositiveS-LAH58 (OHARA)
L5Biconvex PositiveS-LAH58 (OHARA)
L6Biconcave NegativeS-TIF6 (OHARA) / N-SF5 (SCHOTT)
L7Negative MeniscusS-TIH53 (OHARA) / N-SF57 (SCHOTT)
L8Biconvex Positive (1× Asph)S-LAH65V (OHARA) / N-LAF34 (SCHOTT)
AnalysisDetailed analysis available in the interactive viewer above.

Element	Type	Glass
L1	Neg. Meniscus (2× Asph)	S-BSL7 (OHARA) / N-BK7 (SCHOTT)
L2	Positive Meniscus	S-LAH58 (OHARA)
L3	Biconcave Negative	S-TIM2 (OHARA) / N-F2 (SCHOTT)
L4	Biconvex Positive	S-LAH58 (OHARA)
L5	Biconvex Positive	S-LAH58 (OHARA)
L6	Biconcave Negative	S-TIF6 (OHARA) / N-SF5 (SCHOTT)
L7	Negative Meniscus	S-TIH53 (OHARA) / N-SF57 (SCHOTT)
L8	Biconvex Positive (1× Asph)	S-LAH65V (OHARA) / N-LAF34 (SCHOTT)