Thursday, January 08, 2004

Eliminate camera shake

Great images and videos are often ruined by something preventable: camera shake.

Camera shake is the most preventable problem in photographs. It occurs when the camera is unstable, the film ISO (or ISO setting for digital cameras) is too low for the amount of light or the f-stop is set too high on cameras with adjustable apertures.

Most camera shake can be prevented by slowly squeezing the shutter release button instead of pushing or jerking it. When the shutter release is depressed rapidly, the camera rotates clockwise, down and either forward or backward, depending on how it is held.

To see whether a photo has camera shake, note its brightest points of light, called spectral highlights. These are typically reflections of sunlight or flash on metal or glass. If these points appear as a small curve instead of a pinpoint, the problem is from depressing the shutter release button too hard or quickly. By slowly squeezing the button, the camera is more stable when the film or digital sensor is exposed to light.

Stabilize the camera
Stability is the key to eliminating camera shake. The best way to create a stable platform for the camera or video recorder is by using a tripod. When used properly, a tripod can eliminate most movement. (A tall building swaying in the breeze is another story.)

Other ways to stabilize a platform include monopods, sandbags, tabletops, walls and even a cord or chain. The goal is to eliminate as many directions of movement as possible.

Monopods eliminate most up, down and rotational motion but allow other perspective adjustments, particularly in a mobile environment.

A table or any other flat surface eliminates these same movements but restricts image framing.

Bracing a camera against a wall or tree eliminates several directions of movement but also restricts the PJ's options and occasionally her/his ability to frame the image at all.

Make a lightweight, portable option
An inexpensive, lightweight way to stabilize a camera is to attach a cord or chain to a camera or video recorder. The PJ then steps on the cord and lifts the camera to limit vertical motion.

To accomplish this, measure a chain, nylon webbing or a strong piece of cord to the height of the photographer. Cut the material. Next, screw a bolt that is ¼ inch in diameter by 20 threads per inch ( ¼-20) through a chain or a loop in the cord. The length of the screw depends on the depth of the tripod mounting hole and the thickness of the cord.

Thread the screw into the tripod mounting hole (on the bottom of most cameras and recorders). Add a metal washer if needed. Then, step on the dangling portion of the cord, lift against the cord, and the image platform is more stable.

Other preventions
Sometimes camera shake occurs even if a camera is on a semi-stable platform. Using an electronic shutter release (often called a plunger), a wireless remote or even a self-timer eliminates this problem.

With automatic advance cameras, it's often best to take three-frame bursts of photographs. The first and final frames may have motion from depressing or releasing the shutter release button. But the center frame should be sharp.

Additionally, PJs must control their breathing. Before making a photo, frame the subject in the camera viewfinder. Then, take a large breath. Quickly blow the air out and slowly squeeze the shutter release button. After each breath, PJs have three seconds to depress the shutter release before their bodies begin shaking for a new breath of air. If waiting for a particular moment, a photographer can keep breathing like this until ready to make the image.

Enough for now,

No comments: