Today I created a large panorama photo by sending 18 RAW captures to the Photoshop CS5 Photomerge function for editing. A panorama photo was apparently successfully created but when I tried to save it as tiff and return to Lightroom, a message appeared in PS saying that any photo larger than 4GB could not be saved as tiff, that I would have to save it with some other, less large format or method. I wanted to save it in an uncompressed form, thus certainly not as a jpeg. I noticed when I tried again using the "Save As" function, I was given an option to save it as a copy in tiff rather than in layered form. Would such a "copy' remain uncompressed? What disadvantages might there be with saving it as a copy?