Trap focusing requires the photographer keep the shutter pressed (point#6 below) until the object appears at the point where camera is pre-focusing.
- Set custom setting #A5 to AF-ON ONLY
- Set the focus mode to SINGLE SERVO
- Set Auto focus area mode to SINGLE POINT (9 point, 21 point, 51 point or 51 point 3-D will all work)
- If your lens has an A/M switch, make sure it is set to A for autofocus mode.
- Pre-focus the lens for a particular distance. Don't forget that a more convenient way to use this trick is to pre-focus using not the shutter button, but the FOCUS button on the back of the camera can be used. I find this easier and more effective.
- Press and hold the shutter release ALL the way down, the camera shoots only when the selected focus bracket is in focus.
I wonder if forcefully pressing the shutter ALL the way down can damage the shutter release. How much pressure should I apply? Though I know I am sounding dumb, but I want to be sure before I get the new piece broken out of my sheer stupidity.