Dr. Max Weth Optik, was a German lens maker located in Berlin in the 1950s (West Germany). The company is best known for its Telestigmar multi focal lens set, first made in 1955 (sometimes known as Votar Telestigmar). This was a very unique 6-element lens, with the ability to configured in four different focal lengths, with four different apertures: 315mm f/6.3, 250mm f/5, 225mm f/4.5, and 175mm f/3.5. The lens was described in a 1957 article in Modern Photography [1]. The lens has three interchangeable components: N and P are negative and positive lenses, and Z an extension tube, i.e. spacer (the kit also included R, a close-focus extender). When one or two of these are combined with the front lens, V, the different focal lengths are obtained. For example P+V = 135mm. The article suggest that the best “critical sharpness” was obtained using N+P+V=225mm lens. The lens was made in mainly in M42, and Exakta mounts (and custom ALPA).

The rationale behind the lens was that it provided four telephoto lens without the weight of four telephoto’s. It was basically a prime lens with two ancillary rear elements and a spacer. The lens would ultimately be superseded by zoom lenses of similar focal range, i.e. 175-315mm. In 1957 the lens sold for US$220. The most recent prices online are around US$100-300.

Further reading:

1. “The Amazing Tele-Lens of Dr. Weth”, Modern Photography, 21(10), pp.70,71,140 (Oct,1957)
2. “The Magical Optic of Dr. Weth”, Peter Dechert (1992)