To operate the view camera, the photographer opens the shutter on the lens to focus and compose the image on a ground glass plate on the rear standard. The rear standard holds the ground glass in the same plane that the film later occupies—so that an image focused on the ground glass is focused on the film. The ground glass image can be somewhat dim and difficult to view in bright light. Photographers often use a focusing cloth or "dark cloth" over their heads and the rear of the camera. The dark cloth shrouds the viewing area and keeps environmental light from obscuring the image. In the dark space created by the dark cloth, the image appears as bright as it can, so the photographer can view, focus, and compose the image.