Researchers at Tani Electronics Corp. and the Nishi Lab of the University of Electro-communications (UEC) developed a tool that measures the effect of camera shake correction and discovered that the resolution of an SLR camera was reduced by up to 75 percent, due to the vibration generated when an SLR's mirror flips up. Though some cameras try to compensate with a mirror lock-up mode that holds the mirror up for a period of time before releasing the shutter, the study showed that the shutter release itself also caused vibration effects.
But the biggest surprise of the study was the discovery that camera shake was significantly worse when using a light tripod (of approximately 3.3 pounds) than when held by hand.
Furthermore, the increased vibration effect while using the lightweight tripod was even worse with image stabilization features turned on (confirming the advice of most camera manufacturers to turn off image stabilization during tripod use.)
The moral of the story: Unless you have a super steady hand, invest in a decent tripod.
[Via Wired Gadget Lab and TechOn]