The Sigma RS-31 Remote Control is a wireless remote for the Sigma SD1, SD14, SD15 and SD1 Merrill Digital cameras. The remote control allows the photographer to take selfportraits or get into group shots. Used with the mirror lockup function, it can reduce the possibility of image-blurring caused by camera shake, making it particularly useful for macro or telephoto shooting. The RS-31 Remote Controller is an alternative to the CR-21 Cable Release offering a wireless connection to the camera.