As the name suggests a mirror less camera works without the help of a mirror as opposed to a DSLR which has a mirror or a prism which acts as a mirror to reflect the images on to a viewfinder.
These cameras are also called DSLM or Digital Single Lens Mirrorless cameras. Because of the compact size, these are also called Compact System Camera or CSC.
Difference Between DSLR And DSLM
In the DSLR or Digital Single Lens Reflex camera, the light from the object passes through the lens and falls on a reflex mirror. This light falls on a reflex mirror which then falls on a pentaprism which reflects this light to the optical viewfinder or to the camera sensor. What you view through the optical viewfinder is the exact image which you will capture on the camera.
So, how do mirror less cameras work? Here the light is passed through the lens and directly falls on the camera sensor. There is no optical viewfinder in a DSLM. You can see the image on the electronic viewfinder. The electronic viewfinder gives you the exact image of what falls on the camera sensor.
Because of the absence of a reflex mirror and the pentaprism, a mirror less camera is much smaller and lighter. This is a big advantage when you are traveling with the camera. Another advantage of the mirror less camera is that every image will fall on the camera sensor thus giving you the advantage of seeing the camera settings like white balance, contrast etc. You can even have other settings overlaid on the viewfinder. This allows the photographer to see exactly what will be captured by the camera.
DSLR Vs DSLM
When you check how do mirror less cameras work, you find they are different from DSLR cameras. There are other differences too. A DSLM camera is much lighter because of the absence of a mirror and the pentaprism. It is also smaller than the DSLR cameras.
In a DSLR camera, the autofocus works by phase detection which works very fast. Earlier models of mirror less cameras used the contrast detection method which is slow. But the latest DSLM cameras come with both phase and contrast detection which makes the autofocus work fast even in low lights.
We have seen how do mirror less cameras work and the differences between DSLR and the mirror less cameras. Both cameras have their advantages and disadvantages while the mirror less camera scores on bulk and weight.