Carl Zeiss Jena's Exakta short tele — the five-element Biometar 80mm f/2.8 portrait prime.
The Carl Zeiss Jena Biometar 80mm f/2.8 is a short-telephoto prime from Jena, better known in medium format but also offered in the 35mm Exakta bayonet. It sits between the standard and the longer teles in the Exakta line as a natural portrait focal length. The Biometar name denotes a specific five-element Zeiss design distinct from the Biotar and Tessar families used elsewhere in the range.
This is a manual-focus Exakta-mount lens with an 80mm focal length and a maximum aperture of f/2.8. It uses the Biometar optical formula, a five-element design of the Xenotar type. The aperture is set on the barrel and, on Exakta bodies, coupled through the mount's internal actuating lever. Further construction figures such as filter thread and weight are left out here where they cannot be confirmed for the specific Exakta variant.
The Biometar 80mm renders with even sharpness and smooth, well-behaved out-of-focus areas rather than a heavy swirl, giving a cleaner classical look than the Biotar family. The 80mm length places subjects at a flattering distance for head-and-shoulders portraits and works well for general and street use where a slight reach is wanted. Colour and contrast are moderate in the vintage Zeiss Jena manner.
Exakta-fit Biometars are less common than the medium-format versions, so expect to search and to see a range of conditions. Check for haze, fungus and separation inside the glass, and confirm the aperture blades are dry and the ring clicks cleanly. Inspect the coatings for cleaning marks and test the focus for smoothness. An Exakta adapter makes it a usable portrait lens on mirrorless bodies.