Many of the advantages of SLR cameras derive from viewing and focusing the image through the attached lens. Most other types of cameras do not have this function; subjects are seen through a viewfinder that is near the lens, making the photographer's view different from that of the lens. SLR cameras provide photographers with precision; they provide a viewing image that will be exposed onto the negative exactly as it is seen through the lens. There is no parallax error, and exact focus can be confirmed by eye—especially in macro photography and when photographing using long focus lenses. The depth of field may be seen by stopping down to the attached lens aperture, which is possible on most SLR cameras except for the least expensive models. Because of the SLR's versatility, most manufacturers have a vast range of lenses and accessories available for them.