NIKON AI NIKKOR 28mm f/3.5

US 4,099,850 Example 5 — Sei Matsui / Nippon Kogaku

6 elements / 6 groups
f ≈ 28.00 mm
f/3.5
2ω = 74.2°
all-spherical

Focus Mechanism

Unit extension; the whole optical assembly moves object-ward and the final BFD increases at close focus.

Optical Elements (6)

ElementTypeGlass
L1Positive MeniscusE-BAF8 (Hikari) / J-BAF8 class
L2Negative MeniscusN-SK16 / S-BSM16 / J-SK16 class
L3Biconvex PositiveBAFD7 (HOYA) / S-BAH27 / J-BASF7 class
L4Biconcave NegativeE-FD4 (HOYA) / H-ZF6 / J-SF4 class
L5Positive MeniscusN-SK16 / S-BSM16 / J-SK16 class
L6Biconvex PositiveN-SK5 / S-BAL35 / J-SK5 class

Analysis

Detailed analysis available in the interactive viewer above.