Shane Hurlbut writes about his experiences serving as D.P. on the film “Drumline” and how he used shutter angles to drive the story home.
What is shutter speed? Imagine a pie, and that pie has 24 pieces. If the film plane or digital sensor in your camera were to always to see the lens, this would be shutterless. Nothing is obstructing its view with a 360-degree shutter. To the best of my knowledge, this can only be done on digital cameras, unless you pull the shutter physically out of a film camera. At 360 degrees, you will have a lot of motion blur in your action because as an actor moves his arm or his drumstick you are seeing it on all 24 pieces of the pie. If you were to use a 180-degree shutter, which has become the industry standard at 24 fps, you would see motion blur that we have all come accustomed to in the theater. At 180 degrees, the film plane or digital sensor at 1/50 or more exacting 1/48 sec of a second would be seeing the drumstick on 12 out of the 24 pieces.
DSLRs do not line up exactly as a film camera, but the shutter speed is somewhat close. The Alexa, Epic and Sony arsenal of cameras sync with the film degrees. Canon C300s and 500s have unique shutter speed options.
If you now narrow that angle, then the camera is seeing the arm and the drumstick less. Let’s get back to the pie reference. If at a 90-degree shutter or a 1/100 of a sec, you would see the drumstick on only six pieces out of 24 pieces of pie. Your motion blur is going away and it sharpens the image. A 45-degree shutter or a 1/200 sec would see the drumstick on only three pieces. A 22-degree shutter, 1/400 sec would see the drumstick on 1.5 pieces of pie and at an 11-degree shutter, 1/800 sec, you would see the drumstick on 3/4 of a piece of pie. I hope this makes sense.
You are making your view of the lens less frequent, so motion blur is absolutely eliminated. This is why, in still photography, you can suspend a moment. Sports photography uses it a lot, using a 1/4000 of a second to suspend that football player or the ball off of a bat in mid-air. By doing this, you can quickly start to realize that if the film plane is seeing the lens less, then this will require much more light to expose your digital sensor or film negative.
Shane Hurlbut | Read the Full Article