A disadvantage of this is there will be reduction in light that will reach the film or sensor through the small aperture, since the narrower opening lets less light in. That means that these types of lenses are usually not suitable for fast-moving objects which require short exposure times to freeze motion – see lens speed. The amount of collected light can be increased by opening the angle of view, which is achieved with an even shorter focal length resulting in a wide-angle lens. Telephoto lenses are not feasible at a reasonable lens speed.