What is a Compact System Camera?

The Basics:  

A Compact System Camera – also known as a Mirrorless Camera – is a type of camera that uses interchangeable lenses, for example Canon’s EOS M series. The main advantage of a Compact System Camera is that it is smaller and lighter than full sized Digital Single Lens Reflex cameras, while still touting ‘DSLR quality’ images. This reduction in size is made possible by removing the dedicated AF sensor, mirrorbox assembly, and optical viewfinder that a conventional DSLR incorporates. This approach requires that the imaging sensor also has to take over the role of auto-focus, which is generally less effective than the dedicated AF sensor in a DSLR, particular when the subject is moving.