This truly groundbreaking digital SLR camera incorporates a 46 megapixel (4,800x3,200x3 layers) 24x16mm APS-C X3 direct image sensor. The SD1 is Sigma's flagship digital SLR model housed in a solid magnesium alloy body making it extremely lightweight with an overall nice feel and pleasant handling. The weather resistant feature protects the camera from the effects of harsh weather conditions. Incorporating a 24x16mm APS-C X3 direct image sensor, dual "TRUE (Three-layer Responsive Ultimate Engine) II" image processing engines and the 46 megapixel sensor ensures that high resolution images are processed quickly with high definition and a smooth and subtle graduation of color delivering an image size of approximately 35/45 mp in raw/tiff files. This latest technology meets the strictest standards and requirements of professionals and enthusiast photographers for all types of photography.