When I watch some CS:GO videos, I see they have fully static crosshair. For example, in this video,  [NiP vs eXtensive from ESL Major Series Winter 2012](http://www.youtube.com/watch?feature=player_detailpage&v=bZ2Y4O-PYSw#t=585s). I'm not talking about a recoil control thing. I mean that guys in the video can smoothly pull their aim down. However, when I shoot there is a little vibration on my crosshair. I mean very small, left and right. How do they do that?

edit: I painted : [http://i.imgur.com/rxvm1ha.png](https://i.imgur.com/rxvm1ha.png)
compare this videos 
first: 

(sorry 4 the quality, fraps gives me too big file when I choose better resol)
second one: