I think the IS systems are driven by the available technology as much as any other reason. In the 1980's, it was possible to stabilize gun mounts or motion picture cameras, but the systems were large and consumed large amounts of power. I just think the IS systems became practical about the time digital started to replace film.


I wasn't sold on IS until I got the EF70-200mm f/2.8 L IS USM. I've never been able to hand hold at shutter speeds lower than 1/focal length and I usually didn't even like the results until I was a stop or two faster. With IS on the 70-200, I've shot wedding images at 1/30 and been really happy with the images.


Technology has really changed our "sport." Now that the 5DMKII supports ISO 25K, I shoot weddings in the available darkness. Can you imagine telling a wedding pro from the 70's that you were using film with an ISO speed of 25,600, a shutter speed of 1/30 of a second and that you would be capturing 1,500 images between "film" changes. When he regained consciousness, you could tell him the images would beavailable in a cute slide showduring the wedding reception...