I am considering buying the Nikkor NPK 50/1.4 S AI lens. Faster lenses tend to have more distortion. Is this the case for this lens (i.e. compared to the f/1.8 and f/2 versions...of whatever Nikkor variety)? I like the DOF scale markings on the S 1.4 (4, 8, 11, 16). The f/16 marking is rather useless, but I really like having both 4 and 8. Anyway, I do not want to be disappointed, as I do not like distortion. I welcome any comments on its performance.