Wednesday, November 6, 2013

What Causes Motion Blur

TVs and Cameras can experience motion blur.


When people use technology to capture or present images, there is a slight disconnect between the image in media and the image in real life. One type of motion blur occurs when a still camera shot captures an image that moves while the shutter is open. The brain also detects motion blur when an on-screen moving picture is presented too slowly to be interpreted as natural motion.


Flicker Fusion


Any time you view a moving image on a screen you are actually watching a number of still images presented in series. In most cases, if a display presents images at a fast enough rate then your brain will interpret the images as a fluid stream of activity. However, if the images are presented at a rate of 24 frames per second or less then you may be able to detect the flicker of each individual frame. Thus slow frame times will lead to a certain amount of motion blurring, especially when attempting to present fast moving images.


LCD Motion Blur








If you watch a program on a high-definition LCD screen then you may notice that moving images often appear to be a bit blurry. On a TV with a standard 60 hertz refresh rate, motion blur occurs because there is a delay of 16.67 milliseconds during which each pixel displays a single unchanging color. When an object moves quickly across screen, your brain expects that the object will disappear from its earlier pixels more quickly than it actually does. The trailing pixels make the object in motion appear to be blurry.


Camera Motion Blur


When you take a picture with your camera, there is a brief moment during which the camera captures light in its sensor. If the contents of the light that strikes the sensor change while the shutter open then your picture will suffer from motion blur. This can happen because you move the camera slightly while taking the picture, which results in the contents of the entire frame shifting mildly. You can also obtain motion blur in a picture even if your hand is steady if the subject of the picture moves quickly during the shot.


Fixing Camera Motion Blur








There are two primary ways to fix motion blur when taking pictures. The first is to select a faster shutter speed. A quick shutter speed means that there is less time for light to enter the camera sensor and thus less time for multiple impressions to strike the sensor. You can also eliminate nearly all motion blur due to user unsteadiness by securing the camera on a tripod.

Tags: motion blur, appear blurry, blur occurs, blur when, Camera Motion, Camera Motion Blur