The 135mm f/2 has near-mythical status among event and reportage shooters: it compresses backgrounds, isolates a subject from a crowded room, and lets you work a few rows back without feeling like you’re in someone’s face. But at full-frame prices, it’s a hard lens to justify for a working shooter who doesn’t need it every day. There’s a cheaper way to get most of the way there — and it starts with a lens most people already own.