Originally Posted by
conropl
It is a lens thing... the camera should not matter. Westfall says all modern lenses since the 90's should have tripod detection. He even mentioned he 24-105mm specifically as having it. But tripod detection does not stabilize for mirror slap, and it does move some prior to locking in position after the shutter button is first pushed (can take up to a second to settle in). So do not push the shutter button to fast. However, the big whites also have a nice feature where the IS goes a step further when on a tripod, and will help to eliminate the effects of mirror slap... so in the case of those lenses, it is recommended that IS be left on (this includes your 500mm).