With the advent of mirrorless cameras such as Nikon Z series, has the need for focus checking been removed? The answer is not straight forward. In theory ‘yes’ because focus on mirrorless cameras is based mainly on Contrast Detection systems which is the holy grail’ for focussing. However, Nikon decided that for the Z series their focus uses a hybrid AF system. This involves both Phase Detection and Contrast Detection Autofocus pixels, just like they have done with their DSLR’s. In practice I am finding that with the Z series lenses, autofocus is invariably close to ‘0’. However, using F series lenses attached to a Z series body via the FTZ adapter, checking autofocus is more important as there is the increased variability innate to DSLR lenses.