mirrorlessness

Mirrorlessness, also known as mirrorless interchangeable-lens cameras, refers to a category of digital cameras that lack a reflex mirror and pentaprism system. This absence of a mirror is the defining characteristic that distinguishes them from traditional digital single-lens reflex (DSLR) cameras. In a DSLR, a mirror redirects light from the lens to the optical viewfinder. When the shutter button is pressed, the mirror flips up, allowing light to reach the image sensor and capture the photograph. Mirrorless cameras, on the other hand, transmit light directly from the lens to the image sensor.

This fundamental design difference has several implications for camera functionality and form factor. Without the mirror box and pentaprism, mirrorless cameras are typically smaller, lighter, and more compact than DSLRs. Instead of an optical viewfinder, they utilize an electronic viewfinder (EVF) or rely solely on the rear LCD screen for composing shots. The EVF displays a digital feed directly from the image sensor, offering features like exposure simulation, focus peaking, and live histogram.

The removal of the mirror also allows for shorter flange distances, the distance between the lens mount and the image sensor. This can lead to more compact lens designs and greater flexibility in adapting older lens systems. Mirrorless cameras generally offer fast autofocus systems, often employing phase-detection or contrast-detection methods directly on the sensor. They have become increasingly popular due to their advanced features, image quality, and portable designs, catering to both amateur enthusiasts and professional photographers.