What to look for in a… Mirrorless CSC

Interchangeable lenses

Like a DSLR, a compact system camera (CSC) doesn’t feature a fixed lens. Instead, you can swap between lenses depending on the subject you are shooting or the effect you want to achieve. The lens mounts on CSCs are different to those on DSLRs, which means you can’t use DSLR lenses on a CSC without purchasing an adapter to ‘bridge’ the two mounts.

Look, no mirror!

The most significant difference between a DSLR and a compact system camera is the lack of a mirror. Not only does this allow CSCs to be much smaller and lighter, but it also means they’re much quieter in operation. As there is no mirror to reflect the sensor view in a CSC, you will have to use the Live View monitor or an electronic viewfinder instead while composing shots.

Pocketability

Compact system cameras are smaller than the majority of DSLRs. Rangefinder-style CSCs are more pocketable than those styled like compact DSLRs but the grip and handling of the latter can be an advantage.

Viewfinder – or not

The lack of a mirror means CSCs don’t have an optical TTL (through the lens) viewfinder but many DSLRs boast a built-in electronic viewfinder (EVF), a small screen showing the Live View. Others can be fitted with a small viewfinder accessory on the hotshoe.

Light path

In a DSLR, some light passes through the mirror to the AF sensor, but the majority is reflected up to the pentaprism, exposure meter and viewfinder assembly. This system takes up a lot of space, though.

Flange Focal Distance

The FFD in a CSC is significantly shorter than in a DSLR. For example, Canon’s EF and EF-S DSLR mounts have an FFD of 44mm, whereas the Q mount used in Pentax’s CSC range uses a distance of just 9.2mm.

Electronic display

In a CSC, the light strikes the sensor, and an image is generated on the rear screen and electronic viewfinder, if present. This means that the body can be much slimmer and shorter in height.