I recently got a Nikon DF and I learned that it is the only DSLR that can use unmodified Nikon Pre-AI lenses. I am mainly a portrait photographer. I do have some manual AI lenses like the 50mm f/1.2, a 28mm, and a 105mm. I was wondering what the best Nikon Pre-AI (or even non-AI) lenses that I should look for portraits? I would prefer to stick with Nikon branded lenses.