a200 to a700?

You shoot the Sony a700 combined with the Sigma 18-50mm HSM OS 1:2.8, so you have image stabilization in the cam (sensor SSS) and in the lens (OS).

Just in case you did not do so already - make sure you have only one of the two enabled when shooting handheld, as they don't work together but rather overcompensate shake and add blurr in the resulting shot. And also make sure to turn both off when shooting from a sturdy tripod - again, just in case.

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Cheers,
Ralf