Elmarit-M 90mm f/2.8

Introduced in 1959, the Elmarit 90 hit the balance the Summicron 90 sacrificed weight for: f/2.8 speed in a lens you'd actually carry. The first generation (code 11129) ran through the Canadian era; the 1990 redesign (11807) sharpened it for the modern age and lasted until 2008.

It is also the lens most commonly cited for Alberto Korda's 1960 Guerrillero Heroico — the era, the focal length, and Cuban press kit records all point to it, though no primary document names the exact unit.