US 2,799,207 — Günther Lange
| 5 ELEMENTS / 4 GROUPS |
| 80 mm / f ≈ 80.00 mm DESIGN |
| f/2.8 — CALIBRATED STOP MODEL |
| PATENT FIELD 56° / PRODUCT CATALOG 58° |
| ALL-SPHERICAL |
Infinity prescription only; the patent gives no focus travel. The Graflex lens focuses to 2.5 ft (0.762 m).
| Element | Type | Glass |
|---|---|---|
| LI | Positive Meniscus | N-SK16 (coordinate-compatible dispersion proxy; historical supplier unconfirmed) |
| LII | Negative Meniscus | SF4 (coordinate-compatible dispersion proxy; historical supplier unconfirmed) |
| LIII | Biconcave Negative | SF1 (coordinate-compatible dispersion proxy; historical supplier unconfirmed) |
| LIV | Biconvex Positive | K-LaK9 (coordinate-compatible dispersion proxy; historical supplier unconfirmed) |
| LV | Positive Meniscus | SF4 (coordinate-compatible dispersion proxy; historical supplier unconfirmed) |