Target Finder Black Ops 2

The Thermal scope, as introduced in Modern Warfare 2, was the first seen form of electronic-aiming assistance - and Modern Warfare 3's Marksman perk, with its extended marking of enemies, was also similar in effect. In real-life, such technology is a little beyond what we have today: infrared scopes probably the closest to such highlighting of targets.

More advanced targeting electronics are likely to be seen on larger-scale ordinance: missile guidance systems are able to track a moving target autonomously, using a vehicle's heat signature or radar emission to stay locked on. In-game, the target finder is available for the Assault Rifles, SMGs and LMGs. You may only equip a single optic on any given weapon, but any other option remains open when using the Target Finder.
The majority of the Target Finder's effects are fairly obvious: your weapon's iron sights will be replaced with the optic, and enemies within your scope will be marked with a red diamond while you are aiming. The zoom level of this optic is the same as the Rotech sight, or the LMG's innate default:1.5x, a fairly balanced magnification ideal for mid to long ranged combat.

You’ll also benefit from a 90% reduction in idle sway, which can help stay on target when engaging longer ranged enemies. The key downside to this optic is the massive reduction to your peripheral vision: the scope viewfinder occupies less than half of the total screen area while the surround obscures your view.
 This will leave you vulnerable to flanking attacks, as you may simply not see an enemy approaching from the side. For this reason, it's best to make sure you're firing from a safe location - with your back covered either by teammates or equipment. Beyond the loss in peripheral vision, you'll also need to keep a keen eye out for enemies with the cold blooded perk.

Such foes won't be highlighted for you - and so can take you by surprise, if you don’t pay attention to unmarked targets. The Target Finder is a particularly usable optic which provides considerable long-range assistance while having less explicit close-range downsides. It’s great for long-ranged automatic weapons: anything with low-recoil and high ranged damage will perform admirably.

 LMGs are clearly the best fit, then - the Mk48 and LSAT perhaps the two most powerful options when equipped with this electronic assistance. The Assault Rifles can work, too - the longer ranged automatic options, such as the M27and SCAR-H are probably the best fit - but none of the options here are bad with the right playstyle. I'd avoid the optic on SMGs, as such weapons tend to rely on mobility and awareness - and the long-range benefits of the sight are lost on weapons with such low damage and high recoil.
The same applies to any aggressive build - if you plan to be mobile, the loss in awareness will dampen your potential. Still, for those weapons that suit it the Target Finder can almost feel like cheating- and while it is not without downside, the addition of red diamonds marking your forefeels like a luxury. So if you want to suppress the enemy at a furlong's reach, harness this attachment and ride its assistance to victory......just make sure you don't become blinkered to the alternatives. Go here the full overview of Call of Duty Ghost.