CN 211826699 U, Example 1 — Liu Ruijun, Chen Baofeng
| 10 ELEMENTS / 9 GROUPS |
| PATENT f = 33.21 mm |
| MODEL EFL ≈ 33.754 mm |
| F/1.4 |
| 2ω = 45.6° |
| INTERNAL FOCUS |
PUBLISHED — single-element internal focus: negative G3/L31 moves 3.94 mm toward the image side from infinity to the published 0.4 m state (D1 1.00→4.94 mm; D2 6.24→2.29 mm). The source's 0.01 mm D1+D2 rounding difference is retained.
| Element | Type | Glass |
|---|---|---|
| L11 | Negative Meniscus | Unmatched (717295-class dense flint; nd=1.71, νd=29.51) |
| L12 | Biconvex Positive | 729547 — high-index crown class (vendor unproven) |
| L13 | Positive Meniscus | Unmatched (806333-class high-index flint; nd=1.81, νd=33.29) |
| L14 | Negative Meniscus | Unmatched (low-dispersion crown; nd=1.51, νd=81.59) |
| L21 | Biconcave Negative | Unmatched (847238-class dense flint; nd=1.85, νd=23.79) |
| L22 | Biconvex Positive | 729547 — high-index crown class (vendor unproven) |
| L23 | Biconvex Positive | 923209 — high-index flint class (vendor unproven) |
| L31 | Negative Meniscus | 567428 — optical-glass class (vendor unproven) |
| L41 | Biconvex Positive | 741527 — high-index crown class (vendor unproven) |
| L42 | Negative Meniscus | Unmatched (847238-class dense flint; nd=1.85, νd=23.79) |