If I'm using a lens with image stabilization will my camera body detect this and automatically lower the required shutter speed? For example, say I set an aperture of f4 with a non-IS lens, and I want to have a fast shutter speed of 1/800. The camera detects this will lead to an under-exposed photo and will flash a warning at me in the view finder. Then I attach an IS lens, and the image stabilization is enough such that 1/800 is now fine. Will the camera body know about the IS feature and no longer flash a warning at me in the view finder? Does it depend on the camera body? I have a Canon Rebel XS, and I'm thinking of purchasing a 70-200 f4L lens (non-IS). I'm curious whether, if I went for the IS version instead, the camera body would know about the IS feature or if I have to manually compensate and/or ignore the camera's warnings.