Given I have the 75-150mm Series E, would purchasing the 50-135mm f3.5 be too redundant ? I ask because I see it in plenty of John Shaw's books, and it seems to be an old lens that works well with Nikon DSLRs. I don't know if the same holds for the Series E. With a DX body, the 50-135mm becomes a 75-200mm field of view. Not a bad range to have. If anyone has used both, how different is the picture quality ?