Hi, I recently bought a worker C220 and a couple of lenses. This seems to offer great "bang for buck" performance and is clearly very capable . I quite enjoy the slower pace of my "serious" photography with this. This model has two plates on the left side, which are exposed as the lens assy is adjusted outwards. One looks like a distance scale and has curves for each of the popular lens options, 65 - 250mm (although it doesn't look like a depth of focus scale). A smaller plate underneath is a puzzle to me. It has four strips which look like a scale, each starting at x1 and moving through other shaded bands, 1.5 2 3 up to 4. Each of the strips is headed by a focal length, 180-250, 105-135, 80 and 55-65. As an example, the 80mm scale changes from x1 to x1.5 at 7 feet, which seems a little strange. I guess that it is some exposure factor as the lens bellows are expended to close up distances, but my searches seem to indicate that it is to determine the level of adjustment to be made for parallax compensation, used with some lines marked on the viewing screen. Anyone know what this scale is used for? How is DoF determined, do I need a table for each lens? Thanks, Dave..... So much to learn.