Crop factors and adapted lenses
There was something I never understood when it came to crop factors of sensors smaller than full frame. For example, I know that the Micro Four Thirds sensor has a crop factor of 2, meaning that a 14mm lens on, say, an Olympus E-P3 will have the same field of view as a 28mm lens on a Canon 5D MkII. I was okay with this knowledge until I realized that Panasonic and Olympus label their lenses as "14-42mm (28-84mm equivalent)", while a company like Canon just labels a lens as "18-55mm", made more confusing by the fact that its full-frame 5D MkII and APS-C sensor cameras use the same lenses.
So my question is, is crop factor only based on the sensor, or the lens itself? For example, if I put a Canon EF lens set at 14mm on an Olympus E-P3 through an adaptor, would it give me the same field of view as a Micro Four Thirds lens at 14mm? Or would it give me a field of view similar to a Micro Four Thirds lens at 7mm?