Lens Group       The Zuiko Lenses That Never Made It

The Manual For Zuiko Interchangeable Lenses Group dated January 1973 (coded 0173 on the back cover) does not only contain a group photo of the entire Zuiko Lens Group that incorporates two super telephoto lenses that were never marketed, the 300mm/F6.3 and 400mm/F4.5, it also contains the specifications of both lenses. Apparently they were not only designed and prototyped, at least one sample of both lenses must have been assembled for the pictures in this manual.
Why these lenses were cancelled at the very last moment remains a mystery. The leightweight 300mm/F6.3 (600 g.) would have been very interesting for the amateur and for those who want to travel lightpacked. The fast 400mm/F4.5 would have been a must have for the professional sport and wildlife photographer, and a nice alternative for the 350mm/F2.8, weighing 1700g. less.
The same manual mentions three other super tele photo lenses that were 'under development', and possibly also prototyped, but never made it. It does not contain any pictures or specifications of these lenses. They are a 500mm/F5.6, 800mm/F9 and 1200mm/F14. Another brochure also mentions a normal telephoto 160mm/F3.5 lens.
An interesting note also is on the page that describes the zoom lenses. The 75-150mm/F4 was the only one available at that time. Apparently the second zoom lens that Olympus made, the 85~250mm/F5 was originally designed as a 90~250mm lens. In some brochures this lens is displayed, being bulkier than the final lens, suggesting it was designed to be faster (maybe F4 or F3.6).
Then there is the 'L. Zuiko Auto-W 18mm/F3.5' prototype with 12 element in 10 groups, and a fixed 72mm thread. This version was never marketed. The final version is multicoated (Zuiko MC 18mm/F3.5), has 11 elements in 9 groups, a much more convex front element and uses an 49->72mm adapter ring to mount filters.
Another lens that never made it was the manual focus version of the 28-85mm/F3.5-4.5 lens (available as an AF Olympus lens for the OM-707 AF). The lens was prototyped - it appears completely with specifications and a picture in the German Edition Olympus 6, Produkt Lexikon, 1996!
And finally it is worth mentioning that the 40mm/F2 pancake lens was originally designed as a 50mm/F2 lens, with almost the same size and weight, but a longer minimum focus distance.

Top: 300mm/F6.3 prototype    Bottom: 400mm/F4.5 prototype	Right: 28-85mm/F3.5-4.5 prototype

Specifications for the Zuiko 300mm/F6.3

Specifications for the Zuiko 400mm/F4.5

Specifications for the Zuiko 28-85mm/F3.5-4.5

Another Lens Group photo showing the F.Zuiko 300mm/F6.3, F.Zuiko 400mm/F4.5, L. Zuiko 18mm/F3.5 and 135mm/F4.5 Macro prototypes.