There are many options to do that, but today I’ll show you one of them. It’s easy, just find some old footage, which will be blank shot (white or black screen) and with some dirty scratches or hair. Then you need to change blending mode to darken or myltiply and that it all.
When I was searching for such footage, I had a problem to find one in good resolution. I only found the small ones. So because of that I decided to make it on my own. I used the wacom tablet and frame after frame I was drawing the scratches. I set composition to full hd just to have a good quality and it was done!
Here you can download this footage – download.. Feel free to use it anywhere :)
Just remember to put it on your footage, set the blending mode to multiply or darken and thats all!