Speed Graphic (Graflex)
This model was produced during prior to and through World World War Two. Despite the common appellation of Speed Graphic, various Graphic models were produced between 1912 and 1973. The authentic Speed Graphic has a focal plane shutter. The eponymous name “speed” came from the maximum speed of 1/1000 sec. that could be achieved with the focal plane shutter. The Speed Graphic was available in 2¼ x 3¼ inch, 3¼ x 4¼ inch, 5 x 7 inch and the most common format 4 x 5 inch. Because of the focal plane shutter, the Speed Graphic can also use lenses that do not have shutters (known as barrel lenses.)
Operation of the focal plane shutter
The focal plane shutter consists of a rubberized flexible curtain with slits of varying widths that cross the film plane at speeds determined by the tension setting of the spring mechanism. There are 4 slits with widths of 1/8 in, 3/8 in, 3/4 in, 1 1/2 in and “T” (T = “time” setting, used when lens diaphragm shutter is used to control exposure duration. The focal plane shutter is left completely open until manually released. The opening covers the entire area of the film for the size of the camera.) On Speed Graphic models, there are 6 tension settings, adjusted by a butterfly winding knob that increases the speed that the slit crosses the film plane. We send the instructions.