er but briefly to a few of the more simple forms of shutter. Perhaps the simplest and cheapest is the time-honoured "drop. It consists of a slide working in grooves, and provided with an aperture which is preferably made of adjustable length. When released the slide drops under the action of… … shillings upwards, and for most purposes is as good and efficient as any other form. It gives slightly more exposure to the fore- ground than sky when used before the lens, but this defect can be remedied by attaching a sky shade to the upper portion of the opening. Neglecting friction, the time…
Photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
