Tamron 28mm f/2.5 — Adaptall-2 wide-angle prime (02B) with close-focus macro, multi-mount fit
Tamron introduced the 28mm f/2.5 in 1979 as part of its newly launched Adaptall-2 system, which let a single lens body change SLR mounts via a swappable rear adapter. Catalogued internally as model 02B, it filled the fast end of Tamron's wide-angle prime lineup through the 1980s.
The 02B uses Tamron's 'CF' close-focusing wide-angle design, racking down to roughly quarter-life-size reproduction, well inside typical 28mm minimum focus of the time. It accepts any Adaptall-2 adapter: Canon FD, Nikon F, Minolta MD, Olympus OM, Pentax K, Konica AR, Contax/Yashica or M42.
Compact and light for an f/2.5 wide-angle, it trades ultimate speed for a smaller, easier-to-carry package than contemporary f/2 wide primes, and its extended close-focus range makes it usable for tabletop and detail work that most fixed 28mm lenses of the period could not attempt.
Adaptall-2 primes like this turn up regularly on the UK used market, sold as bare lens bodies or bundled with a mount adapter. Buyers should confirm the adapter matches their camera, check aperture blades for oil residue, and inspect elements for haze and light scratching common at this age.