Ondrej Krivanek: A pioneering visionary in electron microscopy.

This article is a short biographical sketch of the life and times of Ondrej Krivanek. The story starts with his early days in Prague, Czechia, and briefly outlines various events from a PhD in Cambridge to post-docs in Kyoto, Bell Labs, and building his first spectrometer at UC Berkeley. Ondrej's pioneering contributions to electron microscopy as Assistant Professor at Arizona State University and later as Director of R&D at Gatan are covered, as well as his return to academia and focusing on aberration correction. The story wraps up with the founding of Nion, the early success of the Nion aberration correctors, and subsequent progress such as building a complete cutting-edge electron microscope and later a record-breaking monochromator. Ondrej continues to be actively involved in design and in running Nion, and while this article ends at the present, further breakthroughs can be expected from him.