A question for you expert photo guys. Since I don't have the access some of you have I need to shoot with long lenses. Probably a 300mm Canon L series with a 2.0x, or a 1.4x attached to it. I know the rule of thumb to prevent blurry photos is if your length is 500mm, no slower than 1/500th shutter speed. Now my question, at what shutter speed does the prop freeze. There is nothing worse than a shot of an airplane in the air with the prop froze like it is on ground display.