US 2,646,721 A — Albrecht Wilhelm Tronnier
| 7 ELEMENTS / 5 GROUPS |
| f = 49.9999 mm (DESIGN) |
| f/1.5000 (DESIGN) |
| 2ω ≈ 46.8° (135 FORMAT, PARAXIAL) |
| ALL-SPHERICAL |
CONSTRAINED_RECONSTRUCTION: unit focus inferred from the Prominent body focusing mechanism; all internal spacings remain fixed and the R11-to-image gap increases from 30.012222 mm at infinity to 32.572237 mm at 1.0668 m, assuming the distance is measured from the film plane.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | BASF7 (Sumita catalog equivalent; production supplier unspecified) |
| L2 | Positive Meniscus | N-SK16 (Schott catalog equivalent; production supplier unspecified) |
| L3 | Positive Meniscus | N-SK16 (Schott catalog equivalent; production supplier unspecified) |
| L4 | Negative Meniscus | FTM8 (Ohara catalog equivalent; production supplier unspecified) |
| L5 | Biconcave Negative | SF2 (Schott catalog equivalent; production supplier unspecified) |
| L6 | Biconvex Positive | N-SK16 (Schott catalog equivalent; production supplier unspecified) |
| L7 | Biconvex Positive | BASF7 (Sumita catalog equivalent; production supplier unspecified) |