All S-lenses come with an effective large lens hood which is slotted onto the accessories mount during transport, saving space.  This fast, wide-angle lens is operates practically without distortion. It is therefore ideal for use indoors or for architectural photos. The SUMMARIT-S 2.5/35 CS mm ASPH. uses two aspherical lens surfaces and special glass with anomalous partial dispersion or high refraction as well as rear-group focusing for the highest performance over the entire focusing range. The central shutter employs powerful springs as energy accumulators and through its patent-pending, innovative design can attain shutter times of up to 1/500 of a second that are also fully synchronized for flash.