Right, my little digital camera just can't get a good photo of the rear element. However, there appears to be no image degradation from the marks, as the link to my sample photos show. I have taken hundreds and hundreds of shots w/ this lens, no issues at all w/ IQ. I actually did once have a couple of good photos of the rear element that were posted here, but when I went to look at the archives, apparently those older postings had been simplified, and the photos removed to save server space or something. Anyway, they're not there anymore on the old thread.