US 6,028,720 — Rolf Wartmann, Udo Schauss
| 6 ELEMENTS / 4 GROUPS |
| f ≈ 103.0 mm (d-line) |
| F/5.6 |
| 2ω ≈ 72° (production, at f/22) |
| ALL SPHERICAL |
Unit focus — entire lens moves via view camera bellows/rail. No internal focusing groups.
| Element | Type | Glass |
|---|---|---|
| L1 | Biconvex Positive | S-PHM53 (OHARA) |
| L2 | Biconcave Negative | N-BALF5 (Schott) |
| L3 | Positive Meniscus | Unmatched (phosphate crown class, ne=1.5223, ve=69.5; no public catalog match — possible special melt or discontinued glass) |
| L4 | Positive Meniscus | S-FPM4 (OHARA catalog equivalent; production supplier unspecified) |
| L5 | Negative Meniscus | N-BALF5 (Schott) |
| L6 | Positive Meniscus | S-PHM53 (OHARA) |