Truth be told, our own fingers and the snap of an SLR mirror give cameras the shakes even when they’re locked down on a tripod. Luckily enough, we got Image stabilization built into modern DSLR lenses that compensates the movement to stabilize the image.
How Image Stabilization Works
Modern DSLRs and video cameras have gyroscopes and accelerometers embedded that detect jerky and shaky movements and provide the input to circuitry that takes action to compensate the shake. A floating lens element sits inside the camera near the lens that moves to and fro to compensate by moving in opposite direction. Checkout the video below after a break:
When Image stabilization can be harmful
Sometimes image stabilization technology can actually deteriorate the image stabilization, especially when used along with tripod. What happens is that Image stabilization mechanism tries to overcompensates and moves around more than necessary. It tries to resist motion which was actually intentional. However, newer smart image stabilization are way better at handling this. So the moral of the story is that turn off image stabilization on older cameras when using a tripod, you should be good with modern ones.