An extensive device for use with a digital camera, including a lens and a display for showing an image received via the lens, is disclosed. The extensive device includes a housing having a window thereon and a cradle for placing the digital camera therein and an optical guiding device disposed inside the housing for guiding the image received via the lens and shown on the display to the window. The window and the lens of the digital camera in the cradle substantially orient the same first direction, so that an image information is recorded via the lens and viewed via the window in the first direction.