Camera Construction

The traditional box camera did indeed closely resemble a box, but as we shall see shortly, this is hardly the reason why the type came to be known by the term box. Here is a picture of the Box Tengor made by the revered firm of Zeiss Ikon of Germany, the firm that went on to make the legendary Contaflex, the world's only twin lens reflex using 35mm film, and the Contax, the camera that rivalled the Leica in scope as well as in workmanship. 

The Box Tengor was no ordinary model, let me say; it was a deluxe camera by the standards of the day, and came with such refinements as a double exposure lock, and two, or more f-number settings.

The classical box camera which grew out of the Kodak Brownie has simplicity of operation as its key feature and can be understood by reference to the accompanying figure. A light-tight metal box carries at one end a simple meniscus (or concavo-convex) lens usually stopped down to f/11 to give adequate definition. Upper and lower film chambers are held on either sides of a cone which can be removed from the back or side of the instrument. The roll of film is held in the upper spool chamber from whence it passes over a roller, then over the picture aperture and is drawn off into a take-up spool located below. Film advance after each exposure is effected by means of a key or knob on the outside of the camera body.

The shutter whose function is to admit light to the film for a fraction of a second is usually speeded at 1/25 sec although some models have two speeds, viz, 1/25 and 1/50 sec. In some of the better makes, two settings are available at the flick of a switch, I and T. ‘I’ which stands for Instantaneous, sets the camera for snapshots in broad daylight. The T setting allows for Time exposures. When set at T the shutter can be opened for any required period of time, a facility that greatly extends the scope of the instrument allowing pictures to be taken under all kinds of dim lighting.

Traditional cameras often came with a fixed focus lens. This is a term that refers not so much to a special kind of lens as it means a lens pre-focussed to yield a sharp picture of anything around 8 feet or beyond. This is by no means the most desirable arrangement, but it frees the amateur from the worry of focussing ; as long as he is working in bright sunshine and has stepped back the required number of paces from his subject, he is assured of a satisfactory picture.

On some types of instrument a rotating plate (or stop) behind the lens with circular apertures of different sizes could be brought into position giving apertures of f/11, 16, 22, numbered on some models as 1, 2, 3, or L, M, S, etc (see next section for more details).

The simplest devices had meniscus lenses with the film often arranged to lie in a curved plane at the picture aperture to compensate for the curvature of field of the lens. Better makes had achromat doublet lens construction with an opening of f/8, sometimes in a simple screw focussing mount enabling the lens to be drawn out to focus on subjects as close as 3 or 4 feet. Paper backed roll film, available earlier in a variety of sizes (120, 127, 828, 620 and others) was universally used giving a range of negative sizes, 6 x 6 cm and 6 x 9 cm on 120 film being common, and a small red window on the camera back showed up numbers printed on the backing paper so that the user could advance the film by the correct amount for each exposure.

The picture here is a magazine advertisement showing the Agfa Synchro Box, a standard design which first made an appearance in 1949 remaining in production until 1958. While based on the traditional design the Synchro Box was a top grade instrument which came packed with features. A yellow filter could be swung into place to darken those pale skies, the camera was synchronized for flash exposures, two f-stops were provided, and the shutter had both T and I settings. The two 'eyes' above the lens are lenses themselves, each forms part of what is known as a reflecting viewfinder, a sighting device which lets the user see what will appear in the picture. Two finders are provided, one for using the camera in the vertical position, the other for horizontal pictures.

The Synchro Box, like many other cameras in its class, took 8 rectangular pictures each 6 x 9 cm in size on 120 roll film.

The Agfa Synchro Box Camera.
Picture courtesy of James Mitchell

The conical box within a camera, known as a film carrier may appear to be a confusing bit of mechanical wizardry to the newcomer, but it is really something very simple. James Mitchell clears up the mystery with his superb pictures. Below is a picture of a Brownie and its carrier beside it.

Another view showing the inside of the Brownie.

And this view shows the film carrier superimposed on the Brownie. As the arrowmarks show, the film travels from the top spool to the bottom one.

Camera photographs courtesy of James Mitchell.