MIRRORLESS
A mirrorless interchangeable lens camera (MILC), frequently simply mirrorless camera, and sometimes also called EVIL (electronic viewfinder, interchangeable lens) features a single, removable lens and uses a digital display system rather than an optical viewfinder. The word “mirrorless” indicates that the camera does not have an optical mirror or an optical viewfinder like a conventional single-lens reflex camera (SLR), but an electronic viewfinder which displays what the camera image sensor sees.
Compared to DSLR cameras, mirrorless cameras are mechanically simpler and are typically smaller, lighter, and quieter due to the elimination of the moving mirror. While nearly all mirrorless cameras still have a mechanical shutter, many also have an electronic shutter, which completely eliminates any sound. Additionally the lack of a moving mirror reduces vibration that can result in blurred images from camera shake.
The first mirrorless camera commercially marketed was the Epson R-D1 (released in 2004), followed by the Leica M8. The Micro Four Thirds system, whose first camera was the Panasonic Lumix DMC-G1, was released in Japan in October 2008.
DSLR
A digital single-lens reflex camera (also called digital SLR or DSLR) is a digital camera that combines the optics and the mechanisms of a single-lens reflex camera with a digital imaging sensor, as opposed to photographic film. The reflex design scheme is the primary difference between a DSLR and other digital cameras. In the reflex design, light travels through the lens, then to a mirror that alternates to send the image to either the viewfinder or the image sensor. The traditional alternative would be to have a viewfinder with its own lens, hence the term “single lens” for this design. By using only one lens, the viewfinder of a DSLR presents an image that will not differ substantially from what is captured by the camera’s sensor. A DSLR differs from non-reflex single-lens digital cameras in that the viewfinder presents a direct optical view through the lens, rather than being captured by the camera’s image sensor and displayed by a digital screen.
DSLRs largely replaced film-based SLRs during the 2000s, and despite the rising popularity of mirrorless system cameras in the early 2010s, DSLRs remain the most common type of interchangeable lens camera in use as of 2019.
POINT & SHOOT / COMPACT
A point-and-shoot camera, also known as a compact camera and sometimes abbreviated to P&S, is a still camera designed primarily for simple operation. Most use focus free lenses or autofocus for focusing, automatic systems for setting the exposure options, and have flash units built in.
Point-and-shoots are by far the best selling type of separate camera, as distinct from camera phones. They are popular for vernacular photography by people who do not consider themselves photographers but want easy-to-use cameras for snapshots of vacations, parties, reunions and other events. Point-and-shoot camera sales declined after about 2010 as smartphones overtook them in such uses. To overcome market shrinkage, compact camera manufacturers began making higher end versions and with a stylish metal body.
Most superzoom compact cameras have between 30x and 60x optical zoom, although some have even further zoom, most notably the Nikon Coolpix P900, which has 83x optical zoom, and weighs less than 300 grams, much less than bridge cameras and DSLRs.
The terms “point and shoot” and “compact camera” are used differently in different parts of the world. In the UK point-and-shoot predominantly means a fully automatic camera, regardless of size or shape. A “compact camera” on the other hand, has a small body, regardless of any fully automatic capabilities. Thus a DSLR can have point-and-shoot modes, and some compact cameras are not designed for point and shoot operation, with the equivalent controls to a DSLR.