mirrorless

Mirrorless cameras, or mirrorless interchangeable-lens cameras (MILCs), are digital cameras that do not use a mirror reflex mechanism. They rely on electronic viewfinders or rear LCD screens to frame and review images, rather than an optical viewfinder as in traditional DSLRs.

Eliminating the mirror allows a shorter flange focal distance, enabling more compact bodies and easier adaptation of lenses from different mounts. Most MILCs use removable lenses and employ electronic or on-sensor autofocus systems instead of solely optical phase-detection.

Development: After early experiments, mainstream mirrorless systems emerged in the 2000s and 2010s, with Micro Four Thirds from Olympus and Panasonic popularizing compact mirrorless cameras, and Sony's full-frame Alpha series driving rapid market growth. By the mid-2010s, many manufacturers shifted emphasis from DSLRs to mirrorless, changing the dynamics of the camera market.

Features and ecosystems: Mirrorless cameras come in full-frame, APS-C, and smaller sensor formats. Popular mounts include Sony E, Canon RF, Nikon Z, Fujifilm X, and Micro Four Thirds. Modern bodies offer on-sensor phase-detect AF, high-quality electronic viewfinders, 4K or higher video, fast continuous shooting, and extensive lens ecosystems, often with interoperability via adapters.

Considerations: While lighter and often more compact, early mirrorless systems faced trade-offs in battery life, lens availability, and EVF latency, though these have improved significantly. The choice between mirrorless and DSLR often depends on user needs, including ergonomics, lens selection, and preferred viewfinder experience.