Vivitar Professional Macro Automatic Extension Tube Set of 3 for Canon EOS (13mm, 21mm & 31mm) Vivitar Professional Macro Automatic Extension Tube Set for Canon EOS (13mm, 21mm & 31mm) # Extension tubes are designed to enable a lens to focus closer than its normal set minimum focusing distance # The extension tubes have no optics # Contains three tubes of different length, a 13mm, 21mm and 31mm # Designed with all the circuitry and mechanical coupling to maintain auto focus and TTL auto exposure # 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 Vivitar Professional Macro Automatic Extension Tube Set of 3 for Canon EOS (13mm, 21mm & 31mm) # 3-Piece Automatic Extension Tube Set is designed specifically for use with Canon digital SLR cameras and lenses ranging from macro to semi-telephoto, and allows the photographer 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. # These 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. # This set contains three tubes of different length -- 13mm, 21mm, and 31 mm -- which can be used individually or in any combination to obtain the desired magnification. These extension tubes are designed with all the circuitry and mechanical coupling to maintain auto focus and TTL auto exposure with most Canon lenses, given there is enough light to activate the cameras AF system properly. # Canon Lens Compatibility Notes: Canon EF-S lenses will not mount on the Extension Tube Set. These lenses include but not limited to EF-S 10-22, EF-S 17-85, EF-S 18-55, and EF-S 60mm Macro. IN STOCK , SHIP THE SAME DAY