Mamiya C220 distance & scale plates

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.

Dave

try page 16

www.xs4all.nl/~aue/mamiya/c220/handleiding.html

Noel

Yes, you will need a depth of field table for each focal length, or a calculator.
My tables are here - Dead Link Removed though any thing designed for the focal length on 6x6 should serve. The distance scale on the C220 is almost usable.

The lower scale is for both exposure and parallax correction. The X1, etc are exposure multipliers (not stops). See Dead Link Removed

For parallax, the upper line in the finder matches the frame displacement at 1.5x exposure compensation, and the line nearer the middle of the finder is for 2x exposure compensation. The line is where the true top of frame will be at those lens extensions. It is done by exposure compensation factors because the effect varies with focal length. The true bottom of the frame extends out of sight, naturally.

I'd say these scales are useful as reminders. The distance scales, though better than the C330 series, are not really accurate enough to set from tables.

Thanks guys, very useful info.