Advice on a shooting subject I've never been able to figure out.

[Richard Lane]

What focal length were you using? Is the image cropped?

Does this happen on other cars with different wheels?

Are you referring to the washed out look at the bottom of the wheel or wheel motion?

How fast is he going?


I'll take a few guesses and I would like to emphasize "guesses."

1) The wheels are over-exposed at the bottom due to the harsh overhead light hitting the bottom of the rim (6 O'Clock position). See the Sun hitting the right front fender. The top part of the wheels are partially blocked by the wheel well.

2) 1/1250sec is not fast enough to freeze wheels. Depending on how fast the car is going 1/2000sec may not freeze them either.

3) The front wheel is vibrating more because he is on a curve and it may not be tracking as steadily (skipping). The back wheel is going slower because he is braking in a turn.

4) Moire' : Two intersecting parallel lines in motion, that can fool the sensor.

http://en.wikipedia.org/wiki/File:Moire02.gif