{"lens":{"id":"praktica-b","displayName":"Praktica B","manufacturer":"VEB Pentacon","flangeDistanceMm":44.4,"electronicProtocol":"mechanical-only"},"body":{"id":"sony-e","displayName":"Sony E (incl. FE)","manufacturer":"Sony","flangeDistanceMm":18,"electronicProtocol":"Sony E"},"compat":{"lensMountId":"praktica-b","bodyMountId":"sony-e","feasibility":"mechanical","af":"n/a","is":"n/a","aperture":"manual-ring","infinityFocus":"yes","adapterExamples":["K&F Concept PB-NEX","Fotodiox PB-NEX"],"caveats":["Aperture is selected on the lens's own ring, but the Prakticar diaphragm is automatic — held open by a rear stop-down lever the camera normally actuates at exposure. A mirrorless adapter actuates nothing on its own, so most PB-NEX adapters include a built-in aperture-actuation wheel to press that lever; choose one over a bare ring, or an automatic Prakticar can sit stuck wide open.","26.4 mm flange clearance — comfortable adapter thickness."],"formatNote":{"match":"match","lensFormat":"full-frame","bodyFormat":"full-frame","cropFactor":null,"message":"Lens image circle (full-frame) matches body sensor (full-frame) — no crop or vignetting concern."}}}