Focus does nothing?

[dro]

Maybe I'm doing something wrong but I saw in the gameplay overview trailer, that when you press Focus it highlights objects/explosives around you. Mine literally just slows down time. I don't see anything that I can't already see plainly. No highlights, no enemy health bars? I saw that in the trailer too. Mine just turns the screen dark and slows down time.

[Jacob]

If you're playing on realistic or hard difficulty, focus capability is limited.