I recently purchased an EF 24mm f/2.8 IS USM from eBay and I'm not convinced the image stabilization is working. Obviously, the switch is set to "IS". With my L series glass, there's usually a little click or whir and can see the glass move through the viewfinder. With this 24mm lens there is no sound or movement that I can discern. Is this normal for this lens? (Or the 28mm IS or 35mm IS for that matter?) How can I tell that if the IS is working? Is there a test I can do? Thanks for your input!
Welcome to the forum. I don't know of a scientific test but...while looking through the viewfinder, toggle the IS switch on and off. There should be a visual difference between "off" (shaky image) and "on" (steady image).
