Made by Agilux in England starting in 1949, the Agifold II was a 6×6 format folding camera. This camera has a 90mm lens, a leaf shutter and shutter speeds ranging from B to 1/300.
For metering it had an extinction meter which uses a sequence of known fractions to determine proper exposure. Here’s how it works….see the little slot at the top of the camera above the word agifold? When you look through it you see a strip with numbered boxes, 1,2,3…. pick the highest number that you can make out and match it up to the scale on the top of the camera….
So for instance, if I see a two on a sunny day like today, the fastest shutter speed I will get is 100 at f4.5, the slowest would be half a second at f22. Then you transfer your settings to the lens.
By the way the dial you see in the background is for determining focus. Line up the double image in the viewfinder, check the scale and then transfer that setting to the lens as well.
So much for fast shots.