A mirrorless camera, also known as a mirrorless interchangeable-lens camera (MILC), is a digital system camera that does not use a reflex mirror to direct light to an optical viewfinder.2 Instead, light from the lens is continuously projected onto the image sensor, and the image is displayed on an electronic viewfinder (EVF) or the camera's LCD screen.23 This design eliminates the need for a moving mirror, resulting in cameras that are generally smaller, lighter, and quieter than traditional DSLRs.234

Because the sensor is always active, mirrorless cameras can offer real-time previews of exposure, white balance, depth of field, and picture style settings, which are not possible with optical viewfinders.2 They also support advanced features such as focus peaking, zebra patterning, and face or eye tracking, which are only available when the mirror is locked up in DSLR live view mode.2 The elimination of the mirror mechanism allows for shorter flange focal distances, enabling more compact and optically advanced lens designs.5

Mirrorless cameras typically use hybrid autofocus systems that combine phase detection and contrast detection, often with AI-driven subject tracking, resulting in faster and more accurate focusing than many DSLRs.25 Some models can achieve up to 40 frames per second with up to 759 focus points, a significant improvement over DSLR capabilities.2 However, the constant power draw from the sensor and display results in shorter battery life compared to DSLRs.2

The first commercially marketed mirrorless camera was the Panasonic Lumix DMC-G1, released in October 2008, which introduced the Micro Four Thirds system.2 Since then, major manufacturers like Sony, Canon, Nikon, Fujifilm, Leica, and others have developed their own mirrorless systems with proprietary lens mounts.2 These include Sony E-mount, Canon RF, Nikon Z-mount, Fujifilm X-mount, and Leica L-mount, among others.2

Mirrorless cameras are now the dominant choice in the interchangeable lens camera market, with many manufacturers phasing out DSLR production.2 They are especially popular among hybrid shooters, videographers, and professionals due to superior video capabilities, faster autofocus, and advanced image stabilization.26 While high-end mirrorless models may be comparable in size to DSLRs, entry-level and mid-range models are significantly more compact.4 For beginners, options like the Canon R50, Sony a6400, and Nikon Z50 are recommended for their user-friendly interfaces and strong performance.6

Some mirrorless cameras also feature electronic shutters, enabling completely silent operation, which is ideal for discreet shooting.2 However, older models with on-sensor phase detection autofocus may suffer from banding artifacts due to repurposed pixel sites for focusing.2 Overall, mirrorless cameras represent a significant evolution in camera design, offering enhanced functionality, improved autofocus, and greater portability.25