This PRAKTICA T2 Canon EF Mount adapter with 42mm thread allows you to attach any spotting scope adapter tube with a 42mm screw thread to a Canon EF camera. Digiscoping adapters allow you to attach a camera to a spottinng scope by way of a tube over the spotting scope eye piece and a T2 adapter to attach the tube to the camera. Care must be taken to select the correct adapter tube that will fit over the eye piece and the correct T2 mount for your model of camera. The PRAKTICA Hydan Series Spotting Scopes work perfectly along side this accessory, and by using this trick you will be able to pinpoint extraordinary detail over huge distances. A technique which is perfect for wildlife photography and astronomy.