Thursday, February 17, 2011

Great Article about Motion Shots

Implying Motion
by Bryan Peterson

When the camera remains stationary – usually on a firm support such as a tripod – and there are moving subjects, the photographer has the opportunity to imply motion. The resulting image will show the moving subject as a blur, while stationary objects are recorded in sharp detail. Waterfalls, streams, crashing surf, and rush hour traffic are but a few of the more obvious subjects that provide motion-filled opportunities. Choosing the right shutter speed for these motion-filled situations is oftentimes trial and error for many shooters but it doesn't have to be.
There are certainly some general guidelines to follow for implying motion, and if nothing else, these guidelines can provide a good starting point for many of the motion-filled situations that abound. The movement of water, whether it be a waterfall, a stream or crashing surf can be easily conveyed at shutter speeds ranging from a 1/4 second to 1 second while moving traffic is usually best conveyed at the longer exposure times of 4 or 8 seconds.
Waterfalls are perhaps the most sought after motion-filled shot by the amateur photographer. They certainly were for me in my early days and even today, when I come upon one of them, I certainly don't hesitate in immediately using an exposure to imply the waterfall's motion. Silver Falls State Park in Oregon continues to be one of my favorite locations for waterfall shooting and the two best seasons are late spring or fall. In this particular image there are actually two things going on and both are working in my favor. From a low viewpoint, I have mounted my camera and Nikkor 12-24mm lens on my Bogen 190CX PRO4 tripod to take advantage of the foreground interest of autumn colored leaves and of course the flowing water. This means that in addition to using the smallest aperture of f/22, I will also be pre-setting my focus to three feet to get the maximum depth of field. Interestingly enough, at the aperture of f/22, I am now assured of recording the slowest possible exposure with the ISO of 200, which my camera is set to.
Additionally, I chose this day to come to the park since it was heavy overcast with periods of light rain and this of course means it was a 'dark' day in the woods which further supported my need and desire to shoot some slow exposures. And finally, as a big believer in using a polarizing filter on overcast/rainy days, (the polarizer will reduce if not eliminate the dull grey glare off of the surface of the water and surrounding fauna), the two stops of light reduction will also 'force' a much slower shutter speed. With my B/W 77MM polarizer in place, and with the dark overcast sky overhead, I soon discovered that at f/22 a correct exposure was indicated at 1 second. The resulting 'long' exposure accounts for the cotton candy like water you see here and the use of an aperture of f/22, (story-telling) accounts for the front to back sharpness. (Nikon D300, ISO 200)
Highway Traffic
It has and will always be my goal to present motion-filled opportunities in the most motion-filled way. Traffic on the highways follow a simple rule; the longer the exposure time, the greater the motion is conveyed. In our first example, and again, with camera mounted on tripod, Photo #1 was shot at f/4 for 1/2 second, while photo #2 was shot at f/16 for 8 seconds. Clearly, the longer exposure of 8 seconds results in a much more dynamic composition. Both of these exposures were made with my NIkon D-2X and Nikkor 200-400mm zoom at the focal length of 400mm, mounted on tripod with my ISO set to 100 and my WB set to Cloudy.
No doubt about it; motion filled subjects are fun to shoot! Heck I love the subject of motion so much that I wrote book about it, Understanding Shutter Speed and it was last year, in my Singapore workshop where I got an idea to add some "man-made motion" to a simple portrait. We'll go from a pleasing, yet static background, to one that is filled with motion in as little as a 1/50 second! Check out the video link below!
All my best,
Bryan F. Peterson/Founder
PPSOP Video Tip

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