Shutter Speed: Decontextualising motion
This one’s easy. The longer your shutter stays open, the more your film (or CCD) is burned in with image.
Shutter speed is—depending on the photographic subject—the exposure control mechanism with either the most or least ’side effects’. Take a mountain, for example; one could simply mount their camera on a tripod, point it at a mountain and leave the shutter open for thirty seconds at a time (provided the film isn’t sensitive and the light isn’t high) and the difference between 30 seconds and 1/30th of a second is negligible.
It is a different story if you’re running through a crowd with the camera in your hands and trying to take pictures of a parade. 30 seconds will leave you with a picture containing only abstract smears of light—if not an outright pure white frame.
In the world of photography, rules of thumb are key. So here are a few:
- The Inverse Law for Handheld Photography
- Generally the lowest shutter speed one can select for a hand-held camera is the inverse of the focal length of the lens. Although we’ll get into the meaning of focal lengths in a later post, if the camera sports a lens that’s set to a focal length of 50mm (considered the ‘default’ focal length in photography by some) then you should set the shutter speed to 1/50th of a second or faster.
- Guidelines For Human Motion
- If a human subject is attempting to stand still for the camera, they will stay crisp up to 1/2 of a second; If a human subject is relaxed, they will stay crisp up to 1/30th of a second.
Important Note: The completely blur-free human subject in motion is not always desirable. While it’s always neat to see an athlete suspended in mid-air, face distorted and muscles strained, as clear as a bell. Moderate motion blur often adds necessary context to an action captured by a photograph.
April 3rd, 2008 at 6:56 am
Huh… Slightly addled, but on the whole I like this post. You’ve got some fresh ideas. But please, write more lucid.