Toronto. I have a POCO 4×5 made by Rochester Camera Co. in the 1890s. This camera uses the dry plates that led to the early success of George Eastman. When Richard Maddox of England invented a successful dry plate formula in 1871, it led to the so-called instantaneous or sub-second photograph. Until the dry plate and later film became popular it was customary to use a lens cap or even a hat as a “shutter” since most photographs took a few seconds or more in broad daylight for a decent exposure.
With the advent of rapid dry plates, a formal shutter became necessary. My camera uses a Bausch and Lomb UNICUM shutter surrounding a rapid rectilinear lens. The dainty device allows a photographer to set his shutter speed to 1, 1/2, 1/5, 1/25, 1/60, or 1/100 of a second plus T and B (Time and Bulb). Focussing is by bellows and a ground (frosted) glass plate viewed without a dry plate inserted, shutter set to B and held or set to T, and the camera’s back opened. The camera has a waist level viewfinder with a tiny ball to level the camera on a tripod.