ENNA MÜNCHEN ULTRA-LITHAGON 28mm f/3.5

US 2,959,100 Example 1 — Enna Werk / Hans Lautenbacher

6 elements / 6 groups
f ≈ 28.00 mm
f/3.5
2ω = 75°
All-spherical retrofocus

Focus Mechanism

Unit focus; close state modeled by increasing BF from 35.227689 mm to 38.836352 mm for a 0.30 m object-to-image distance.

Optical Elements (6)

ElementTypeGlass
L1Negative MeniscusS-BSM10 equivalent (OHARA; legacy SK10-class, patent nd/vd)
L2Positive MeniscusUnmatched legacy flint (625/356; exact catalog type unresolved)
L3Biconvex PositiveN-SK4 (SCHOTT)
L4Positive MeniscusUnmatched legacy flint (625/356; exact catalog type unresolved)
L5Biconcave NegativeSF4 (SCHOTT)
L6Plano-ConvexJ-SSK1 equivalent (HIKARI; legacy SSK1-class, patent nd/vd)

Analysis

Detailed analysis available in the interactive viewer above.