In 1987, Canon did something either breathtakingly bold or commercially reckless, they abandoned the FD mount entirely and launched EOS with the EF system, a fully electronic interface that made every FD lens instantly obsolete. EOS stood for Electro-Optical System, though Canon also nodded to the Greek goddess of dawn, a poetic way of announcing "we're starting over and you're coming with us whether you like it or not." Canon's engineers felt that mechanical linkages were charming relics destined to bottleneck autofocus speed, so they ripped them out, tucked motors inside, added electromagnetic diaphragms, and built a high-speed electronic system. The Canon faithful were livid, naturally, but professionals quickly discovered that EF's speed and precision made their beloved FD glass look like it was focusing through cold honey while wearing mittens.

The EF mount's 44mm flange distance and 54mm throat diameter let them create ambitious lens designs: ultra-fast primes, monster telephotos, and optical formulas impossible with mechanical constraints. It's the photographic equivalent of Ikebana's principle of ma (間), negative space as a design element, where what you remove matters as much as what remains. By cutting out mechanical couplings, they made room for electronic sophistication. Over 30 years, EF metastasized into a vast ecosystem, EF-S for crop sensors, EF-M for tentative mirrorless flirtations, EF-Cine for filmmakers. Even after RF lenses arrived in 2018 with the smug confidence of youth, EF lenses thrive via adapters, backed by 170 million units and the kind of professional trust you can't manufacture, only earn by not failing spectacularly when someone's livelihood depends on you.

The EF mount proved that progress sometimes requires arson, that compatibility can become a gilded cage, and that users'll forgive you for obsoleting their gear if the replacement is superior rather than just shinier. Like Ikebana's deliberate cuts that shape growth, Canon's break from FD wasn't destruction, it was radical pruning that let everything after flourish. They demonstrated that enduring designs aren't the ones clutching to the past, but the ones with enough conviction to set it on fire and walk away without looking back.