I have recently purchased a 80mm Macro lens for my 645 Mamiya. This lens has a MAG SPACER ring adjustment. The instructions explain how to set this ring with and without the spacer. What confuses me is a statement in the instructions that call this a "built-in floating system." When I am not using the spacer does this ring need to be set. If I am just taking close ups does this ring come into play? Alan Tippett ************************************** See what's new at http://www.aol.com