I used a FotoDiox FD-to-NX adapter to fit this monster Canon FD 400mm 1:4.5 S.S.C. lens on my NX1. I was combing through vintage lenses at a pawn shop in Tucson, Arizona and was just about to walk-out after not finding anything of interest. The guy behind the counter said: "Hey, did you see this one". He reached behind a pile of old cameras and pulled-out this lens. It looked in excellent shape for a 1975 lens, so then I looked at the price -$30!! Are you kidding me?!
I now call this my M.O.A.L. (Mother of All Lenses)
This wider angle photo shows the points of interest for the two photographs below
Photo of high-rise at 400mm
Crop showing decent-sharp detail
Church tower at 400mm
Here's a few links to read further about this lens and photographer's comments:
https://www.photo.net/discuss/threads/canon-fd-400mm-f-4-5.117744/
https://www.dpreview.com/forums/post/53569225
http://www.mir.com.my/rb/photography/companies/canon/fdresources/fdlenses/400mm.htm#f4.5
