JP 2008-040033 A Example 1 - Sigma / Yoshino
| 6 elements / 5 groups |
| f = 16.6 mm (design 16.67 mm) |
| F4 (design F4.02) |
| 2ω = 73.7° |
| 1 aspherical surface |
| Rear-group internal focus |
Rear-group internal focusing: G5 moves 3.5896 mm toward the object from infinity to 0.30 m while the first-surface-to-image track remains 56.2503 mm.
| Element | Type | Glass |
|---|---|---|
| G1 | Negative Meniscus | Hoya E-FL5 / Hikari J-LF5 light flint (nd=1.58144, νd≈40.9) |
| G2 | Negative Meniscus | Hoya FC5 / Ohara S-FSL5 / Hikari J-FK5 fluor crown (nd=1.48749, νd≈70.4) |
| G3 | Biconvex Positive | Hoya TAC2 / Ohara S-LAL61Q class lanthanum crown |
| G4-L1 | Biconcave Negative | Hoya FD140 / Ohara S-TIH14 / Hikari J-SF14 dense flint |
| G4-L2 | Biconvex Positive (1x Asph) | Hoya M-TAF401 class lanthanum flint (soft match; Example 2 exact) |
| G5 | Biconvex Positive | M-BACD5N (Hoya) / S-BAL35 / N-SK5 crown |
Detailed analysis available in the interactive viewer above.