Snap focus is, as far as I know, unique to the Ricoh GR series.
Snap focus ‘snaps’ into action when you press the shutter without first giving the autofocus time to work – just one solid press on the shutter and it focuses at the ‘snap’ distance and takes the shot.
Let’s say the snap distance you have set in the camera is two metres. Then when you judge you are two metres from your subject – press the shutter without the half press. That overrides the autofocus and it is instant because it doesn’t need time to acquire focus.
You can set the snap distance at various distances from one to five metres. To set the Snap focus quickly, press the macro button and spin the front dial. The choices are 1, 1.5, 2, 2,5, 3.5, and 5 metres.
I see Snap focus being useful in shooting on the street but especially if I was at a demonstration, or in a crowd where everyone was engrossed in looking at something. I would shoot in shutter priority and auto ISO to make sure I could freeze the action with a quick shot.
When I think of Snap focus I think of Garry Winogrand, who shot with a 35mm film camera, often holding the camera out at arm’s length. In other words, he often shot without looking in the viewfinder, knowing by experience where the camera was pointing.
I generally shoot in Aperture Priority, and that’s what I was shooting with when I photographed the buildings down Trinity Lane in Cambridge, looking towards the river. Then I turned sideways to see this couple standing next tom me, photographing the lane. I had Snap focus set to one metre, and it crossed my mind that I was not sure whether the woman was one metre away from me.
As it worked out, she was within the zone of sharp focus and you can see from the crop of the full frame, the lens is sharp and Snap focus works. Thinking about the strengths of the camera, I might switch to shooting shutter priority generally so that I can shoot ‘from the hip’ as it were, and freeze the action.