This year's air show during Fleet Week was a special one. Why? Well, according to a sharp photog at this past weekend's air show, the air conditions produced shock collars (i.e., Prandtl-Glauert singularities), something the occurs as moisture condenses in high-pressure regions on an aircraft. Or something like that. Photographer Bhautik Joshi explains how he captured the shock collars:

Conditions were exactly right this weekend (high humidity, fast aircraft) to produce a few shock collars (sometimes known as Prandtl-Glauert singularities, shock eggs or vapor cones) at the Fleet Week airshow in San Francisco.

These are not pictures of planes breaking the sound barrier - the shockwave of the plane creates high-pressure region in which moisture condenses producing the beautiful but transient shock collar, as seen above.

The neat thing here is that you can use pretty pedestrian camera gear - in this case, a canon 7D with the low-end 70-300mm lens - to sharply capture some spectacular, transient physical effects.