As per the title, ppl seem to fire at me from miles away when I'm stood still in stealth yet ppl can almost walk right upto me in stealth and I can only see them a few foot away, what's the deal ??

have you played Crysis before? many of our eyes are use to the distortion when people use stealth. Crysis 3 is even easier cuz there is a blue/red tint to them. easy pickings.