Canon EOS 5D Mark III Instruction Manual (en)

When you use the IS lens’ built-in Image Stabilizer, camera shake is 
corrected to obtain a sharper shot. The procedure explained here is 
based on the EF24-105mm f/4L IS USM lens as an example.
* IS stands for Image Stabilizer.
Set the IS switch to <1>.
Also set the camera’s power switch to 
Press the shutter button halfway.
The Image Stabilizer will operate.
Take the picture.
When the picture looks steady in the 
viewfinder, press the shutter button 
completely to take the picture.
About the Lens Image Stabilizer
The Image Stabilizer cannot correct “subject blur”, when the subject 
moves at the time of exposure.
For bulb exposures, set the IS switch to <2>. If <1> is set instead, 
Image Stabilizer misoperation may occur.
The Image Stabilizer may not be effective for excessive shaking such as 
on a rocking boat.
The Image Stabilizer may not be effective when you use the EF24-
105mm f/4L IS USM lens for panned shots. 
The Image Stabilizer can operate with the lens focus mode switch set to 
either <AF> or <MF>.
When using a tripod, you can still shoot with the IS switch set to <1> 
with no problem. However, to save battery power, setting the IS switch to 
<2> is recommended.
The Image Stabilizer is effective even when the camera is mounted on a