Fotodiox Lens Mount Adapter, Pentax K Lens to Canon EOS Camera, for Canon EOS 1D, 1DS, Mark II, III, IV, 1DX, 1DC, 5D, 5D Mark II, III 7D, 50D, 60D, 60D, Digital Rebel T3i, T4i, T5i, SL1, and C300, C500
The Fotodiox PK-EOS Lens adapter allows you to place your favorite Pentax K Lens on your Canon EOS camera body.  This adapter gives you the ability to use your irreplaceable prime lens and saves you the cost of purchasing new lenses.  The adapters are precision made to insure the perfect fit. The lens will fit physically, but the automatic diaphragm, auto-focusing, and other functions will not operate correctly while using this adapter. In this case, "stop-down mode" will need to be used when metering, since the lens does not have the ability to have its aperture controlled by the camera body. You can shoot in manual or aperture priority mode. Infinity focusing is guaranteed.