MAKING A FERROTYPE CAMERA.
The following instructions explain how to make a cheap camera for taking por traits on ferrotype plates 3f in. by in. A portrait lens of 5-in. focus should be pro cured and the camera made to suit it. The ferrotypes arc slower than gelatine plates, a portrait-lens is often a necessity, whilst the box camera can be freed from dust more readily. A suitable box camera may consist simply of two boxes fitting one in the other (see Fig. S7). The outer box lens will probably be fitted with an outer jacket (which screws into a flange for at taching to camera front), in which the lens is moved backwards and forwards by a rack and pinion for focussing (A, Fig. 88). To make the dark slide, groove and rebate three pieces of the form and size shown in Figs. 89 and 90, and mitre the ends. In one piece gouge out a part of the middle, shown by the dotted semicircle in Fig. 89 ; stop about s in. from each end. This forms has in the top a slot an inch or two long, for a thumbscrew to clamp together the inner and outer boxes. Rails R, at back, take the focussing screen and slide, and the fine focussing is done with the rack and pinion on lens. As ferrotypy is a positive process, each picture has to be separately exposed. Where only two or so pictures are required, this may be done with the repeating-back, but a battery of lenses for taking a number of pictures in one expo sure is the general plan.
a trough to hold the drippings from the plates, and it may be covered with metal. In the top of the two slides at x (Fig. 91) is a wide slot that receives a tongue B in the top rail. This top rail is shown by Fig. 92. Place the two mitred corners together in the bench, and, having made a saw-cut across, insert and glue in a strip of veneer. Fix the top bar with the front tongue cut away as in dotted lines in Fig. 93, and recessed at v to take a narrow strip of velvet. Now cut the pieces A ,B c D (Fig. 91), and glue and tongue together A B ; attach B to the rest with a strip of opaque cloth, making a board 41 in. by
3, in. having an *-in. rebate on three sides. Fit into the grooves of the framework, and glue on stops at the back to prevent com plete withdrawal. A strip s is glued to the sides to form a shoulder which shuts down on the top of the camera and helps to ex clude light. Fix silver wires, bent as in Fig. 94, 94 in. apart, two in each side, to take the plate horizontally and vertically. These project into the slide in. Glue in the centre of which is a rubber-lined tank used for developing, and connected with it are three rubber balls, each containing one of the three necessary solutions capable of being forced up into the tank in turn by pressing the ball, whilst turning a tap pre vents the liquid from running back. The whole is supported upon a tripod having a sort of cupboard at top for bottles, etc.
the guiding strips for the slides z z (Fig. 88). Fix in the slide against the wires a piece of ground glass, rough side inward:. ; insert the slide in the camera and focus. Remove the slide gently and insert a frame work made by joining four pieces 41. in. by The construction of the camera enabling the plates to fall one at a time is shown in Fig. 95 ; A is the lens with rack and pinion T., to which may be fitted a simple pull-up-and-down shutter ; c is the focuss ing screen, guided forward into position by the nut D ; E E are side rails, guiding the fall of the plate and holding it in an upright position : F and G are open chain ; in. in. ; adjust the ground glass so that it will register correctl:i with the slide, and fix. Cut a board 4e in. by in., and attach to its inner side a flat spring to hold the plate in position. Hinge this board at the top and put a button at the bottom to fasten it, and the apparatus is complete.