I currently have the Nikkor non-AI 50/2 H, but I have not gotten back any results from it yet. How does its faster cousin, the 50/1.4 S, compare? I do not need the extra speed, and so my question is in regard to image quality (resolution, sharpness, bokeh, etc.). Also, I gather the 50/1.4 S is not a radioactive lens (i.e. no thorium, etc.), but please correct me if I am wrong about this.