VOIGTLÄNDER ULTRON Vintage Line 28mm f/2 Aspherical

JP 2022-100641 A — Yoshihisa Yomogida, Yuki Shibata

10 ELEMENTS / 7 GROUPS
f = 28.50 mm
F/2.0
2ω = 75.4°
2 ASPHERICAL SURFACES (1 ELEMENT)

Focus Mechanism

Source near station: ZD0=430 mm plus LT=60.2274 mm and 1.93 mm extension gives 49.22 cm. All lenses and stop move together. The rounded prescription instead computes about 50.98 cm; this source discrepancy remains unresolved.

Optical Elements (10 physical)

ElementTypeGlass
L1Negative MeniscusBSC7 (HOYA) / N-BK7 (Schott) (inferred coordinate counterpart)
L2Plano-ConcaveE-FD2 (HOYA, patent nd/vd match) / SF2 (Schott) (inferred coordinate counterpart)
L3Plano-ConvexTAFD35 (HOYA, patent nd/vd match) (inferred coordinate counterpart)
L4Biconvex PositiveTAFD35 (HOYA, patent nd/vd match) (inferred coordinate counterpart)
L5Biconcave NegativeS-TIH14 (OHARA, patent nd/vd match) (inferred coordinate counterpart)
L6Biconcave NegativeS-TIH1 (OHARA) / SF1 (Schott) (inferred coordinate counterpart)
L7Biconvex PositiveS-LAC14 (OHARA) / N-LaK14 (Schott) (inferred coordinate counterpart)
L8Biconvex PositiveH-ZLAF68C (CDGM, patent nd/vd match) (inferred coordinate counterpart)
L9Negative MeniscusJ-PSKH8 catalog equivalent (patent 630581; production supplier unspecified) (inferred coordinate counterpart)
L10Neg. Meniscus (2× Asph)NBFD3 (HOYA) / S-LAH63Q (OHARA) (inferred coordinate counterpart)