Well the Wollensak Triple Convertible I was suppose to get fell through. It looks like I will end up with a 300mm APO Sironar-N because I can get one for a steal. The size and weight doesn't bother me. I know it is a fine lens on its own merit but I am always curious about lens performance (more for the sake of interest than any practical application). So, here is my question...how much better would a Sironar-S be as far as image quality over the Sironar-N? The lens will be used on an 8x10 camera; shots will mainly be pictorial so the larger image circle of an -S does not matter; enlargement will not exceed 30" X 40" but rarely beyond 20"x24"; mostly black and white. If I placed a 20x24 print from a 300mm APO Sironar-N next to one from a 300mm Sironar-S, enlarged from 8x10 film, would I even see any difference? This wouldn't alter my decision as I can't afford the -S anyway....I am just curious about actual image quality differences (size, weight, filters, cost, etc. do not matter)!

Thanks for the information!