DE 2444954 A1 Claim 2 — f′ = 90 mm
| 8 ELEMENTS / 4 GROUPS |
| f′ = 90 mm patent example |
| F/4.5 |
| 105° published coverage |
| ALL-SPHERICAL |
Unit focus by camera bellows; no internal focus groups. The focus slider varies only the final back-focus gap.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | FK3 (Schott inquiry glass) |
| L2 | Negative Meniscus | SF5 (Schott) |
| L3 | Biconvex Positive | SSK2 / N-SSK2 (Schott) |
| L4 | Biconcave Negative | LLF3 / QF2 class (inferred, d-code 561468) |
| L5 | Negative Meniscus | SK12 / S-BAL42 class (Schott/Ohara equivalent) |
| L6 | Biconvex Positive | SK3 / H-ZK4 class (Schott/CDGM equivalent) |
| L7 | Negative Meniscus | BaF11 / S-BAH11 class (Schott/Ohara equivalent) |
| L8 | Negative Meniscus | N-FK5 / FK5 (Schott) |
Detailed analysis available in the interactive viewer above.