To my knowledge the S was made by Schnieder and the N was made by Rodenstock .. I have owned them both over the years .......The N is a later lense, multicoated for better contrast and in my opinion a better lens...

The problem with Schnieder lenses is that they eventually flake heavily in the glued area in the black out on the outside parimeter of the lens giving it speckeld appearance.. Some call it Schnieroisis .... In lenses past the excessivensess of this drove me nuts and in one case it cost me $500 when I went to sell the lens......Schnieder said they could fix this but it was expensive......For this reason I will never buy anouther Schnieder lens...

If you want my Caltar 210 N f 5.6 multicoated lens it is $385 with $15 shipping and would include insurance ...It is in a Copal 1 shutter and fully functional....It is a nice near mint lens that comes with a Calumet felt lens wrap ( all nice lenses should have lens wraps) and a 67mm Hoya UV filter.....It will come with lens caps both front and rear ( all nice lenses should have lens caps both front and rear) ....I would rate this lens a solid 9 to 9+ .To find anything nicer you should be buying a new lens.......It is mounted on a Toyo 6.2 lens board and if you want this it is $20.

John Cremati johnjohnc@att.net