Image Stabilization
Nothing says amateur like an accidental crooked shot.


broadcastCam
Commercial broadcast cameras do not readily contain mage stabilizers. These cameras are heavy and well balanced for sitting on your shoulder, sometimes all day. And if they are not shoulder mounted then they are usually sitting on a very expensive and extremely sturdy tripod. Either way it’s much easier to take steady shots with them.




consumerCam
Consumer camcorders are just the opposite. They are small so your shoulder cannot carry them making them very unsteady. Your arms carry the weight. Even though they don’t weigh very much it is very hard to keep a steady shot with just your arms. The reason for this is they just don’t carry enough mass to resist hand movement. This is where image stabilization comes in.


There are three types of image stabilizers built into consumer camcorders.
They are:

* Optical image stabilizers (OIS)
* Electronic image stabilizers (EIS)
* Digital image stabilizers (I don't even know if they still make this one. It was the worst).



Optical image stabilization (or OIS) uses prisms to compensate for camera shake.
Using motion sensors to tell if the camcorder is moving based on information about pitch (tilting), and yaw (panning), the optical system compensates for the jitters.
The lens uses tiny built in gyroscopes to detect the shake. When camera shake is detected the gyros send signals to a computer chip to figures out which way to have the prisms compensate.



Electronic image stabilization (or EIS) is quite different.
Your camcorder records light to a CCD image sensor (Charged Coupled Devise). Your camera probably has a 1/4 inch CCD if it’s a small consumer camcorder. Pay more and you might get a 1/3 inch CCD. Some even have 3 CCD’s for better picture quality. So lets say your CCD has approximately 400,000 little pixels that can each register a chunk of light. Except the camera really only records lets say 320,000 of those pixels of light. What?! That’s quite a waste of CCD image area. Well not really, today's CCD chips do a pretty good job of recording some nice crisp images for us. But what happens with those extra pixels? Well, that’s for the EIS. Think of a picture as the entire 400,000 pixel CCD. Now take a sheet of paper the same size as the picture and cut a square of about 3/4 of the sheet out of the center. Now you will have kind of a picture frame that represents the 320,000 pixels that get recorded. Put the cutout sheet on top of the picture and when camera shake is detected the cutout sheet slides around the picture to offset the shake.

Many modern chips provide a resolution that surpasses NTSC standards. You can get excellent video quality with less than 400,000 pixels on the CCD. If your camcorder has more pixels than that, the odds are good that it can handle electronic stabilization without degrading the image. Theoretically OIS should be better because the prism allows use of the entire 400,000 pixels but I think with the quality of CCD chips these days the difference is negligible.

The best method by far to eliminate camera shake is to turn off the OIS or EIS and use a tripod.