I'm having trouble figuring out how to tag targets with the binoculars on the PS3 version of Crysis, can someone help?

I'm not sure if you're still wondering how, or even playing this game still, but I can tell you if you've played Crysis 2, you should know it doesn't work the way it does in its sequel 'cause it's more for scouting out guys than it is tracking them. If you tried getting the trophy for it, which I did on the 360 (though it being an achievement), you just have to make sure when you use the binoculars, the enemy highlights in red.