I have a new 70-200 2.8L lens that is soft. Unfortunatly I do not have time right now to send it off for a warrenty repair for a few weeks. I need to slightly sharpen a bunch of files from a recent shoot. I find Lightrooms sharpening features to be a bit lacking so I prefer to use unsharp mask in cs4. Is it better to sharpen files as JPEGs or as DNGs? Or does it really even matter?