This medium telephoto macro lens is ideal for both digital SLR cameras and 35mm film SLR cameras. The 70mm focal length gives an equivalent field of view as SIGMA's popular 105mm macro lens when used on digital SLR cameras with an APS-C size image sensor.The design of this lens makes it suitable for taking pictures in all situations from infinity to 1: 1 macro, both with natural light conditions or flash.A Special Low Dispersion (SLD) lens and two high refractive index SLD lenses provide excellent correction for all types of aberrations and produce an exceptional level of optical performance. Sigma's super multi-layer lens coating reduces flare and ghosting, and helps create a natural color balance.The floating focus system provides extremely high optical performance from infinity to 1: 1 Macro. more info