Opteka Auto Focus DG EX Macro Extension Tube Set for Canon EOS 1D 1Ds 5D Mark 2 3 II III 6D 7D 10D 20D 20Da 30D 40D 50D 60D 60Da 70D 100D 300D 350D 400D 450D 500D 550D 600D 650D 700D 1000D 1100D 1200D Rebel SL1 XT XTi XS XSi T1i T2i T3 T3i T4i T5 T5i Kiss

Extension tubes are designed to enable a lens to focus closer than its normal set minimum focusing distance. Getting closer has the effect of magnifying your subject (making it appear larger in the viewfinder and in your pictures). They are exceptionally useful for macro photography, enabling you to convert almost any lens into a macro lens at a fraction of the cost while maintaining its original optical quality. The extension tubes have no optics. They are mounted in between the camera body and lens to create more distance between the lens and film plane. By moving the lens father away from the film or CCD sensor in the camera, the lens is forced to focus much closer than normal. The greater the length of the extension tube, the closer the lens can focus. The Opteka Auto Extension Tube Set contains three tubes of different length, a 12mm, 20mm, and 36mm, which can be used individually or in any combination to obtain the desired magnification. Opteka's Auto Focus extension tubes are designed with all the circuitry and mechanical coupling to maintain auto focus and TTL auto exposure.