How to do it ? First of all go to video settings and make at least PostProcesses effect on low now you need to have ARCO or RCO in the game, then click RMB ( for optics ) go to the Big zoom like this http://bit.ly/16EmDg1 then click again RMB for unoptic and now Optic and press "/" or "leftCtrl + RMB" and you'll see a weird effect that is little bit disturbing for the eye.