The function of post-production.

The function of post-production is to refine and enhance the video qualities. Without post-production the whole video would have to be shot in one take, with man-made effects being present and the filter being manually changed, for example, Ok Go's 'Here it Goes Again' is a one take music video, though it is very basic and has only one scene and not much need for any extensive editing. If you compare this to a heavily edited and major use of post-production, like Velvet Revolver's 'Come on Come in' you will see the drastic change in quality however some people may argue that the editing and the effects are perhaps too much, depending on whether that was the style you were going for in the first place.