i replaced my original canon 50 1.4 lens purchased last week with a new one, as the original was determined to be busted. i took the new one out today and noticed that many of the shots i assumed were centered turned out to be skewed to the left once downloaded. in the viewfinder all is well, but the downloaded images are off a bit. i did a quick indoor test and noticed that where i assume i'm framing the edges, in fact i get more in the downloaded image that i had anticipated. the center point seemed okay, just a bit to the left (not as bad as the outdoor shots). does this have anything to do with a "crop factor"? what am i missing? why have i not noticed this before with other lenses? do i need to adjust anything or am i losing my mind... i'm shooting with a rebel 300D.