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Message: <blockquote data-quote="typo" data-source="post: 3496673" data-attributes="member: 83808">I've been trying to find out some info on the frequency  and amplitude of the shakes, and less successfully, trying to find out the response profile and time lag for the Canon IS correction.It's not particularly easy to find articles on normal, healthy individuals but I did find a nice simplistic statement that said the hand shakes at 8-10hz, the fingers at 17-20 hz and the elbow at 3 to 5hz. Seems reasonable to expect that when using a binocular all three would be involved, but probably which predominates would depend on an individual's physical make up and glassing technique.. Then it gets complicated. There is a tendancy with old age for the 8-10hz hand shake to move to 3 to 5hz, and if weight and or tension is applied to the thumbs then a 3-5hz shake can develop, and something more complex happens to the fingers.I only found one comment about Canon IS technology it and might have been directed at cameras not binoculars. It said IS was most effective at 10hz. Total speculation, but it seems an interesting possibility that perhaps those who find the Canon IS most effective have predominantly 8-10hz shakes? Others that find it less effective might be troubled by other frequencies? I doubt it's as simple as that.David</blockquote>