Terminator 3: Dawn Of FateControl introduction sequence
During the opening screens, press L and R to zoom in the image in the background.
Turret gun zoom
When you get to use a turret gun in certain parts of a level, click Left Analog-stick to zoom in 3x. This will help you see what you are shooting at, and result in better aim.
On most weapons, you can zoom in by 3x pressing R.
Easy Skynet Tech points
While zoomed in, aim for the neck of most enemies and their heads will pop off. Each head is worth Skynet Tech points.