KODAK ENLARGING EKTAR 100mm f/4.5 — Optical Cross-Section & Ray Tracing

Home / Lenses / Kodak / KODAK ENLARGING EKTAR 100mm f/4.5KODAK ENLARGING EKTAR 100mm f/4.5US 2,279,384↗, Example 6 — Fred E. Altman
5 ELEMENTS / 3 GROUPS
f ≈ 100.36 mm
F/4.5
52° FULL FIELD
ALL-SPHERICAL
Focus MechanismUnit focus by enlarger bellows or lens-stage movement; the close-focus state is a representative 3× enlarger conjugate.
Optical Elements (5 physical)ElementTypeGlass
L1Biconvex PositiveUnmatched (vintage barium crown class, 611/572)
L2Biconcave Negative (weak rear)BAK1 (SUMITA catalog equivalent for patent coordinate; production supplier unspecified)
L3Biconcave NegativeUnmatched (vintage dense flint class, 605/382)
L4Negative MeniscusJ-LF7 (Hikari) / LF7 class (575414 light flint; Δnd +0.00001, Δνd +0.11; equivalent; the original Kodak melt is not known)
L5Biconvex PositiveUnmatched (vintage high-index lanthanum flint class, 744/458)

Element	Type	Glass
L1	Biconvex Positive	Unmatched (vintage barium crown class, 611/572)
L2	Biconcave Negative (weak rear)	BAK1 (SUMITA catalog equivalent for patent coordinate; production supplier unspecified)
L3	Biconcave Negative	Unmatched (vintage dense flint class, 605/382)
L4	Negative Meniscus	J-LF7 (Hikari) / LF7 class (575414 light flint; Δnd +0.00001, Δνd +0.11; equivalent; the original Kodak melt is not known)
L5	Biconvex Positive	Unmatched (vintage high-index lanthanum flint class, 744/458)