Which camera maker has the best autofocus for moving subjects?
May 22, 2021
Autofocus systems have become very sophisticated over the last few years. In the third of our Nobody Does It Better series, Angela Nicholson looks at which camera manufacturer makes it easiest to get moving subjects sharp.
Let’s start with a bit of background… Most of the light that exits the lens on a single lens reflex (SLR) camera is reflected up by the mirror into the viewfinder but a small amount passes through and onto a secondary mirror which reflects it towards the dedicated autofocus sensor.
A small lens assembly splits the light so that it forms two images on the line or cross type sensors on the autofocus (AF) sensor. If the two images align, the lens is focused on the subject, but if their alignment is not correct and the images are out of phase, the camera knows which direction to move the lens focusing group and by how much. This process is known as phase detection focusing.