PENTAX SMC PENTAX-A★ 135mm f/1.8

US4447137 Example 2 — Asahi / Yasunori Arai

7 elements / 6 groups
f = 134.99 mm
F/1.8
2ω = 18°
all-spherical
fixed rear element focus

Focus Mechanism

Fixed rear element extension: L1-L6 move together while L7 remains fixed at the rear.

Optical Elements (7)

ElementTypeGlass
L1Positive MeniscusS-BSM16 (OHARA) / N-SK16 / BACD16 class
L2Negative MeniscusS-BAH28 (OHARA) / BAFD8 class
L3Positive MeniscusS-LAL14 (OHARA) / LAC14 class
L4Negative MeniscusS-TIM25 (OHARA) / N-SF5 / E-FD5 class
L5Weak Positive MeniscusS-BAH27 (OHARA) / BAFD7 class
L6Positive MeniscusK-LaFn11 (Sumita) / H-LaF72 class
L7Positive MeniscusJ-LAF01 (Hikari) / H-LaF51 class

Analysis

Detailed analysis available in the interactive viewer above.