VOIGTLÄNDER HELIAR (Symmetric) f/4

US 716,035 — Carl August Hans Harting

5 ELEMENTS / 3 GROUPS
f = 100 (normalized)
F/4.0
2ω ≈ 43.6°
ALL SPHERICAL

Focus Mechanism

Inferred unit focus — all groups and the stop move together by 12.72 mm. The modeled 1.0 m endpoint is object-to-image distance at 100 mm scale; no focus schedule is published. Intermediate distance labels are approximate.

Optical Elements (5 physical)

ElementTypeGlass
LaNegative MeniscusUnmatched Glass I (patent nD; estimated Abbe 42; supplier unspecified)
LbBiconvex PositiveUnmatched Glass II (patent nD; estimated Abbe 57; supplier unspecified)
LcBiconcave NegativeUnmatched Glass I (patent nD; estimated Abbe 42; supplier unspecified)
Lb'Biconvex PositiveUnmatched Glass II (patent nD; estimated Abbe 57; supplier unspecified)
La'Negative MeniscusUnmatched Glass I (patent nD; estimated Abbe 42; supplier unspecified)