I just acquired a Schneider Symmar 180f5.6 Lens (older version - 1970's I think ) on Ebay and I was wondering what your experiences have been in terms of perfom ance of this lens. It is in a Compur shutter. I will be using it as an exclusive lens for my 4X5 Speed Graphic. It is also for B&W only. What do you think its p erfocrmance for colour negative will be?