US 2,186,621, Figure 1 — Ludwig Bertele
| 7 ELEMENTS / 3 GROUPS |
| DESIGN f = 100 (NORMALIZED; SCALED 0.5× TO 50 mm) |
| DESIGN F/1.50 |
| ALL SPHERICAL |
Modeled unit focus: the patent prints only the infinity prescription. The Contax Sonnar focuses as a unit through the camera's helicoid, so the whole lens and stop move objectward 3.14 mm at the modeled 0.9 m object-to-image endpoint; this extension is calculated, not a patent value.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | 671472 — catalog coordinate (supplier unconfirmed) |
| L2 | Positive Meniscus | 671472 — catalog coordinate (supplier unconfirmed) |
| L3 | Biconvex Positive | 489701 — fluor-crown class (supplier unconfirmed) |
| L4 | Biconcave Negative | Unmatched (739282 — dense-flint class; supplier unconfirmed) |
| L5 | Plano-Concave Negative | Unmatched (523509 — supplier unconfirmed) |
| L6 | Biconvex Positive | Unmatched (658512 — SSK-class dense crown, near N-SSK5; supplier unconfirmed) |
| L7 | Negative Meniscus | Unmatched (589612 — crown class, near SK5; supplier unconfirmed) |