Lens surface defects

Hi Andrew,

I'm a huge fan of your tutorials and the proud owner of most of the VC product line. I have 2 questions.

First the easy one. When I use any of the "F" keys in AE, the funtionality seems to be locked to Mac shortcuts (i.e. - launching widgets etc.). How do I get AE to respond to the "F" keys?

Second, and a little more challenging. Have your seen Pierre Michele's Fire Flower spot (http://trapcode.com/gallery/Fire_flower_h.mov)? It's quite amazing and I've been attempting to replicate some of the effects. However one "effect" has eluded me. At about the 1 minute mark there is an explosion of sorts and the resulting burst of light brings into relief what appear to be lens surface aberrations. While most of us spend our time trying to eliminate these "defects", I find this one adds a degree of realism. How would you go about achieving this effect?

Thanks, and great truck accident tutorial. Keep 'em coming.

Kevin Nelson