CSC versus DSLR
For anyone interested in the world of imaging, you'd have to live under a rock not to be aware of the invasion of Compact System Cameras (CSC / mirrorless). Since they've arrived onto the scene, CSC manufacturers, such as Fujifilm, have consistently introduced advancements in technology to the point where CSCs now equal and in many cases surpass DSLRs. And it's more than just their obvious size and weight advantage. In a head-to-head comparison, it's abundantly clear why many professional photographers and dedicated DSLR users are making the switch to a CSC as their mainstay camera.
CSC (MIRRORLESS) DESIGN
CSCs (Mirrorless) do not require the Mirror mechanism in front of the sensor since they do not offer an optical viewfinder. This allows the design to be much more compact offering a smaller camera dimension as well as less weight.
LENS SIZE AND WEIGHT
The lenses that are designed for CSCs (Mirrorless) have less space to travel since the mirror mechanism is no longer needed in the body of the camera. This shortening of the distance allows lenses for CSCs (Mirrorless) again to be much smaller in design adding to less weight in the overall system.
IMAGE QUALITY: WHY THE TIE?
The larger / heavier DSLRs are perceived as providing better image quality. However, a lot of CSCs like Fujifilm's X series offer an APS-C size sensor - exactly the same size as most DSLRs. In fact, Fujifilm's X-Trans Sensor goes one step further by removing the Optical Low Pass filter to offer less moire and better colours at higher resolution. This provides image quality that rivals some Full Frame DSLRs.
DSLRs use an external Auto Focus sensor to determine focus. CSCs, on the other hand, such as in FUJIFILM's X-Series use the camera sensor to determine focus versus a separate AF sensor. This tends to make focusing more accurate, especially when shooting wide open with fast aperture lenses.
OPTICAL VIEWFINDER VS. ELECTRONIC
DSLRs offer an optical viewfinder, which can make it challenging to accurately focus depth of field. CSCs most often feature an electronic viewfinder (EVF). The advantages of an EVF over an optical viewfinder are striking. One can review/playback the image through the EVF which is especially important in bright sunny conditions and much faster than continuously checking the LCD on a DSLR. Depth of Field can also be previewed much easier through an EVF.
DSLRs are generally louder due to the mirror mechanism swinging up and down every time a shot is taken. This takes away the ability to capture certain scenes without disturbing the moment, such as those at weddings or capturing wildlife. Since CSCs do not have a mirror, the camera operation can be 100% silent and less intrusive in more quiet environments.