Japanese-made enlarger lens sometimes marked Aetna Optix. AKA Perfex, Prinz, Soligor, Ampex, etc.
Aetna Coligar 75/3.5
| Dimensions | 75 mm |
|---|---|
| Focal Length (mm) | 75 |
| Max Aperture (f) | 3.5 |
| Min Aperture (f) | 16 |
| Aperture Type | Curved 5 |
| Elements | 3 |
| Rear Mount | M39 |
| Front Thread | N/A |
| Serial Numbers | 180710 |
16:9 –
http://forum.mflenses.com/aetna-coligar-t11283.html