Which areas of the screen can set off the shutter when touched? When the aspect ratio is 4:3 or 3:2 or 16:9, you could touch the area covered by the 81 AF points to set off the shutter. When the aspect ratio is 1:1, you can touch the area covered by the 63 AF points to set off the shutter. Related articles Why is focusing at night difficult? Why does the LCD screen show 81 focus points when I press the multi-function Q button? Comments 0 comments Please sign in to leave a comment.