Nikon and Pentax

9 and 12 researched events on one shared scale. Nikon 1917–present, Pentax 1919–present.

The axis stretches where either maker has research and collapses where neither does, so a year sits opposite the same year on both. Event counts differ because research depth differs, not because one company did less.

Read either maker on its own: Nikon · Pentax