Apparently the 135mm f2 Rokinon is an outstanding lens optically - like literally jaw dropping good. At ~$500 new (I wish I could find one on the used market!!) it seems like a poor mans Zuiko 150mm f2 - a lens that I covet.. Obviously the drawback for most is MF - but it turns out I really enjoy MF. I used a legacy 135 f2.8 the other day at a sporting event with very solid results from a focusing perspective. For giggles I could purchase a Nikon/Canon FF mount...and give myself the ability in the future to BOTH: 1. Purchase a 2x teleconverter giving me an effective FOV of ~ 540mm!! at F4. (sigma has a reportedly very good 2x teleconverter for the Nikon mount for ~$180 on the used market) 2. Purchase a focal reducer giving me a FOV of ~ 192mm and even more light than F2... To me this seems like a lens that might open up some very interesting possibilities from wildlife to landscape to people photography (event/portrait) that right now my lens lineup simply cannot provide. Am I crazy to think that this is a solid idea? Has anyone else done something like this with other long MF lenses?