A multi-focal length range image capturing device including a device body, an image capturing circuit, and a processing circuit are provided. The image capturing circuit performs image capturing based on a focal length setting and accordingly generates an image signal. The processing circuit controls operations of the image capturing circuit and outputs an image according to the image signal. The processing circuit controls the image capturing circuit being operated in one of a plurality of image capturing modes according to a switch triggering signal. When the image capturing circuit is operated in a first image capturing mode, the image capturing circuit sets the focal length range to a first preset focal length range, so as to select the focal length setting within the first preset focal length range. When the image capturing circuit is operated in a second image capturing mode, the image capturing circuit sets the focal length rang to a second preset focal length range, so as to select the focal length setting within the second preset focal length range.一種多焦段影像擷取裝置，其包括裝置本體、影像擷取電路以及處理電路。影像擷取電路基於焦距設定值進行影像擷取，並據以產生影像訊號。處理電路控制影像擷取電路的運作，藉以依據影像訊號輸出影像。處理電路依據切換觸發訊號控制影像擷取電路操作於多個影像擷取模式其中之一。當影像擷取電路操作於第一影像擷取模式時，影像擷取電路將其焦距範圍設定為第一預設焦距範圍，藉以在第一預設焦距範圍內選取焦距設定值。當影像擷取電路操作於第二影像擷取模式時，影像擷取電路將其焦距範圍設定為第二預設焦距範圍，藉以在第二預設焦距範圍內選取焦距設定值。
