For those of you who fall for these "swirl finding light" gimmicks, know that I can see swirls using an incandescent light bulb...
Halogen lights...
Or direct sunlight...
I actually show and explain how to do that on one of my DVD's, which is where those captures came from. None of those options cost more than a few bucks. Those swirl finding lights are priced on crack. If I can make my camera show it, then YOUR EYES can see it. Don't fall for the hype. Get yourself educated!