jim,what you are describing is proper exposure, not over exposure. . . the camera is a tool, the metering is based on a 18% gray. You make adjustments to your exposure based on the subject, light, and what you as the artist want to achieve with the image. Over exposure is, in my view, a term used to describe the condition of the exposure, not the way you set up the camera. .. "proper" exposure is what it is. For high ISO one must not underexpose but "shoot" for the proper exposure . . . I think it may just be semantics . . . ? If you over expose an image you really are talking about losing detail and pushing the image past it's "proper" exposure . . .