I have returned the lens I had for a refund but I need to purchase one as I have now completely sold off all my canon gear which included the 17-55 f2.8 lens so I need this lens to replace it. Before I returned it I had done the following shots (see flickr link). Can some others with the lens perhaps do similar shots and let me know the sharpness you are getting from it. Lens performed like this from 12mm to say 23mm. Have done a number of shots with this same focus position with the same results. I just want to be know that the majority of other copies perform properly at these focal lengths with this type of shot. This is to give me confidence to purchase another one. IS is off on the lens, small focus square is on the persons face. Info is shown on the LR screen shot. Have included comparison screen shot from LR4, original shots and 100% crops of two images. These shot were taken to further test the lens before returning it. 12-35mm Panny - a set on Flickr Your input greatly appreciated.