SIGMA 30mm f/2.8 (DP2 Merrill)

JP 2013-156459 A Example 4 — Sigma / Kōno

8 ELEMENTS / 6 GROUPS
f ≈ 29.6 mm
F/2.8
2ω ≈ 52.1°
1 ASPHERICAL SURFACE

Focus Mechanism

Front-group unit focus: G1 (L1–L5 + aperture stop) translates forward along the optical axis.

Optical Elements (8)

ElementTypeGlass
L1Biconvex PositiveS-LAH58 (OHARA)
L2Biconcave NegativeS-TIM25 (OHARA)
L3Biconcave NegativeS-TIM28 (OHARA)
L4Biconvex PositiveS-LAH58 (OHARA)
L5Biconvex Positive (1× Asph)S-LAL59 (OHARA, probable)
L6Negative MeniscusS-TIM2 (OHARA)
L7Negative MeniscusS-TIL6 (OHARA)
L8Biconvex PositiveS-LAH79 (OHARA)

Analysis

Detailed analysis available in the interactive viewer above.