Hi all: I snagged a Regula King KG camera today. It has a built in extinction meter. I have two questions of anyone who knows anything about this camera: 1) There are numbers at the base of the rewind knob, some letters too. What do they mean? Is it a way of setting the ISO of the camera or some sort of reminder of a setting or some such thing? 2) How the heck do I use the extinction meter? I have worked out that I'm to read off the least dim number I can see but I don't know how to translate that to either f-stop or shutter speed. Thanks all.