Bronica's 645 macro — the leaf-shutter Zenzanon-PE 100mm f/4 Macro for close-up ETR work.
The Bronica Zenzanon-PE 100mm f/4 Macro is a short-telephoto macro lens for the Bronica ETR 6x4.5 medium-format system. It belongs to the later PE generation of Zenzanon optics for the ETRSi era, offering close-focus capability that the standard primes lack. On the 645 format the 100mm sits in the short-tele range while adding dedicated macro performance.
This manual-focus lens uses the Bronica ETR leaf-shutter mount, with a focal length of 100mm and a maximum aperture of f/4. It carries the in-lens Seiko leaf shutter shared across the ETR system, so flash synchronisation is available at all speeds. It is corrected for close-distance work; exact reproduction ratio and other construction figures are left out here as they cannot be confirmed from the sources at hand.
The 100mm macro suits close-up subjects such as product, nature and detail photography while also working as a short portrait lens at normal distances. The longer focal length gives comfortable working distance from small subjects, and the flat-field correction favours copy and reproduction work. On medium format it renders fine detail with smooth tonal transitions.
On the used market this macro is less common than the standard PE lenses and tends to command a higher price for its specialised design. Check the leaf shutter for even firing across speeds and inspect the glass for haze, fungus and separation. Confirm the aperture blades are dry, that the focusing helicoid moves smoothly through its extended macro range, and that the mount couples cleanly to the body.