Zeiss' 50cm f8 Fernobjektiv

The longest lens that Carl Zeiss in Jena manufactured for 35mm cameras was a 500mm f8 lens it referred as a "Fernobjektiv" or Far lens. Part of the text below first appeared in an article I wrote for the 2014 Spring/fall issue of Zeiss Historica [Vol 36, no.1]

50cm f8 Fernobjektiv on a postwar Panflex and a Nikon SP.

In the late 1940s, as Zeiss was trying to figure out what company it still was and what market it should aim for, the Jena factory completed a run of 40 Fernobjektivs, supposedly all in the post-war Flektoskop mount (#s 3412641—3412680, order #907, 8 August to 15 November, 1948). When the Jena facilities finally got around to some kind of regular production, new Fernobjektivs came out in mounts for the East German Zeiss Flektometer housing or with adapters for Exakta or in the M42 thread. Production continued into the early 1960s.

This Fernobjektiv uses the external bayonet mount. It works equally well on a BR-1 ring.

So how did the 50cm Fernobjektiv pictured here end up in the Panflex mount? The serial number  (#3412655) is within the same 1948 batch that were supposed to be in Flektoskop mount. So it must have been intended for the pre-war Panflex. Were a few of that batch made and sold in the Panflex mounting?

The lens itself is a single component achromat doublet in a long-focus design. Such a simple design is capable of excellent sharpness and contrast particularly in the center of its field—provided the lens is confined to a modest aperture and narrow coverage. The famous long-focus lenses offered by Novoflex use a similar optical design. The finish of this particular lens is good if not spectacular. A nice modern black crinkle finish was applied over a smooth black coating with the exception of the diaphragm and focus rings. The glass is T-coated. It takes readily-available 77mm accessories. Apertures close down to f45 with a manually-controlled iris mounted nearly 16cm (seven inches) behind the glass. The focusing helicoid is set forward and just behind the glass. The lens focuses as close as six meters (19.1 feet) with a nearly 360 degree turn of the focus ring. Only the glass moves; the diaphragm remains stationary.

Mounted on a Panflex with a Contax or Nikon rangefinder camera attached, the lens balances on its rotatable tripod bushing. Weighting only 1.627 kilos (4.5 pounds), the lens should be handholdable. However, the focusing ring is set so far forward and has such a long turning that focusing while trying to hold a camera steady becomes an exercise in frustration. This is particularly true if one is trying to follow a moving object.



Using a BR-1 ring, this lens mounts on any F mount Nikon, requiring on a slight shift of the focus to bring infinity into sharpness.
Like all lenses with focal lengths longer than 250mm, the Fernibjektiv vignettes on a reflex housing. This is due to the small throat of the Contax/Nikon bayonet system.

On a Panflex, the Fernobjektiv vignettes.

However, on a Nikon F, it does just fine and is capable of nice, sharp results.

Immature female Coopers Hawk Accipiter cooperii at our birdfeeder. It did not come for the seeds.