Wondering what is a compact system camera? It's a term that came into use some time ago, in that crossover period when DSLRs were still dominant but mirrorless cameras were starting to make headway… but they weren't commonly known as mirrorless cameras back then.
Instead, pundits started to refer to mirrorless interchangeable lens cameras – at that point, predominantly the super-compact Micro Four Thirds cameras (opens in new tab) released by Panasonic and Olympus – as "compact system cameras" (or "CSCs").
This differentiated them from traditional compact cameras (opens in new tab) and point-and shoot cameras (opens in new tab), which had fixed lenses and smaller sensors, and DSLRs (opens in new tab), which have a larger sensor, optical viewfinder and mirror mechanism.
In short, then, 'compact system camera' was typically synonymous with mirrorless camera (opens in new tab) – though often in a pejorative way, as if to suggest that these cameras were inferior to "proper" DSLR cameras with full-size lenses and sensors.
Essentially, take all the silly arguments about APS-C and Micro Four Thirds that still exist today, and throw in a bunch of silly arguments about mirrorless technology (namely aimed at the electronic viewfinder and sensor), and you have an idea of the kind of contempt that was often directed at CSCs.
Oh, how the times have changed.
Where the Panasonic G1 and Olympus PEN E-P1 were once derided, nowadays the term CSC can essentially be placed on any mirrorless camera with an interchangeable lens – from the small-but-mighty Panasonic GH6 (opens in new tab) and OM System OM-1 (opens in new tab) to the omnipresent APS-C Fujifilm X-T4 (opens in new tab) and Canon EOS M50 Mark II (opens in new tab) to the full-frame Sony A7 IV (opens in new tab), Canon EOS R5 (opens in new tab) and Nikon Z7 II (opens in new tab).
Nowadays, then, the term compact system camera is barely used – though you still occasionally hear it uttered by old schoolers, and muttered at the odd very closeted camera club.
Best mirrorless cameras
(opens in new tab)Best Micro Four Thirds cameras
(opens in new tab)Best compact cameras
(opens in new tab)Best point-and-shoot cameras
(opens in new tab)Best APS-C compact cameras
(opens in new tab)Best DSLRs (opens in new tab)