Friday, January 7, 2011

There's More Than One Way to Stop Time...

When taking a photograph, we must consider the setting as well as what we want the photo to look like. At times we may want a blurry, out-of-focus photo, while at other times we may want a photo to be sharp and in-focus. Using a slower shutter speed would reduce the sharpness of the photo because it would give more time for camera movement to affect the image. However, using such a shutter speed also allows a photographer to capture a scene over time, creating a sense of motion in a photograph. On the other hand, a fast shutter speed can freeze objects in motion, as in the photo below.
This photo was taken using a 1/60th of a second exposure combined with a flash to light up the subject.  The key to freezing the motion is limiting the amount of light exposed to the camera sensor, or a piece of film. If the amount of time of exposure can be controlled on a camera, then this effect can be achieved. Usually, the flash on a camera has to be able to sync with the shutter speed being taken, but built-in flash units are typically unable to sync with shutter speeds of approximately 1/250th of a second. As shutter speed is increased, light exposes the sensor for less and less amount of time.  Indoors, shutter speeds anywhere near 1/250th of a second will create dark photos.  Nevertheless, there are occasions in which motion is too fast to even be captured by a 1/250th second exposure, such as a falling droplet of water or a bullet speeding through the air.  In order to capture these moments, many photographers use a technique, which was popularized by Harold Edgerton, in which a 2 second exposure is used in a completely dark room.  An external flash unit with is connected to the camera, and triggered during the 2 second exposure at the precise time at which the object passes by. This essentially simulates taking a photo using a shutter speed faster than 1/250th of a second, but this also keeps the object lit and captured mid-motion, as shown in the photos below. 

In these photos, I am using a setup that is detailed at The company sells a pre-made kit to help make photos such as these and many more, but you can also make a kit yourself for far less! All it takes is a camera with shutter speed controls, an old external flash unit, a hotshoe adapter, an Arduino microcontroller, and the external sensors for the type of photo that you wish to take. All of the necessary supplies(besides the camera) can be purchased for a grand total of less than $50. It is a great way to branch out in your photography and learn more about how photography works at the same time.

No comments:

Post a Comment

About Me

My photo
I am a sophomore in college, studying Biochemistry and math, but I am a pilgrim for knowledge. I seek neither greatness nor acknowledgment, but rather to experience and understand the complex world of ours. My desire for this experiential journey of mine is to gain knowledge and wisdom and, more importantly, to form strong bonds of friendship with the individuals around me. This journey began in December of 2008, when a friend of mine died at the age of 17. In his short life, he had changed lives in ways that I never have done. I was struck by the beauty of the life that had been lost, and I made a promise that day to reach out to people around me; to live a life not wasted. My eyes were opened. My life was changed. My journey had begun.