Has anyone any experience of the Schneider 50 f2.8 Comparon-S. I can't find any info about it on the web. Is it a 4 or 6 element lens. Also how would it compare with the 50 f2.8 El Nikkor. My long serving f4 El Nikkor has started to show fungus and clouding on the internal elements. So my preference is towards the Nikkor. I print no larger than 12x10.