The first point however that the reader must decide is whether he will work by artificial light or by daylight. Each may be said to possess certain advantages, and with many the question resolves itself into one of personal convenience. Artificial light is, or should be, fairly constant in intensity, and if adopted there will probably be less waste of material through miscalculation of exposure. But if the source of light employed be other than a mixed jet, or the arc-light, if in fact it be of low intensity, negatives of a somewhat delicate type will be required in order to produce enlargements of the highest excellence. If the negatives are dense and strong, illuminants of low intensity, like oil or gas, do not possess sufficient penetration to duly register the denser portions of the negative, and the enlargements so made are apt to be deficient in half-tone, and hard. With well-graded negatives of suitable quality, however, most excellent enlargements may be produced by artificial light. When artificial light is used work may be carried on at any time of day or night, in winter or summer. Those who adopt the daylight plan will, of course, be subjected to greater restrictions, at any rate, during the winter months, but amateurs who take a real interest in the work will do well to adopt the writer's plan, and provide themselves with apparatus for each method of working.
ENLARGING BY DAYLIGHT.
There are two ways of enlarging by daylight. The first involves the exclusion of all actinic light from a room except that which passes through the negative. The alternative method of working is to employ an ordinary enlarging camera, such as are made by Middlemiss, or Lancaster. It is desirable, but not necessary, if the first plan be adopted, to secure the exclusive use of a room. One with a northerly aspect should be chosen, for if sunlight falls upon the window shadows will at some period of the day fall upon the negative, and produce unevenly lighted enlargements. An upper room will be most suitable, and, if the light be a northern one, and there are no trees or buildings to obstruct the view, a reflector may be dispensed with. If external objects intervene, however, one must be employed. It should be fixed outside the window-sill, at an angle of 45°, and should be capable of adjustment. Let it be the full width of the window, and securely fixed for obvious reasons. A plate-glass mirror is effective, but expensive. A large drawing board painted dead white also answers well, but should not be left outside exposed to the weather.
Fig. 1.Side View Ditto.
Provision for excluding the light from the room is best secured by making a wooden frame large enough to fit closely against the window frame. Upon this a piece of stout calico should be tightly strained and secured with tacks. It should then be sized, and when dry will be as tight as a drum; it must then be covered with two thicknesses of stout brown paper pasted on. The frame is shown complete in Fig. 1. Now at A.A. B.B. screw two strips of wood, the distance apart must be regulated by the size of the negatives to be enlarged. The ordinary camera is intended to be used as the enlarging camera, and the distance from C. to C. should be just equal to the size of the back portion of the camera. On the lower rail BB screw a piece of 9 in. board to form a shelf or support D. for the enlarging camera. Make a frame E. of ½ in. wood 1 in. deep, the same size as the back of the camera, and screw to the shelf and top rail AA. Now carefully cut away the brown paper and calico from the inside of this frame, at the part marked H. and paste strips of brown paper round it so as to prevent any light passing except through the opening H. A strip of felt should be tacked all round the large frame to prevent any light from creeping in between it and the window frame. A couple of turn buttons will keep it in position. A firm table should be placed against the window close up to the wall to form a support for the enlarging easel. Now a little care must be taken in fitting up this portion of the apparatus, and it is better to have something more exact than the propped-up drawing board or printing frame, which is sometimes recommended. Get a carpenter to run out two V shaped rails as shown in Fig. 2 at CC. They should be about the length of the table, and screwed down upon it. Procure a cheap drawing board about 15 x 12, and to the under side affix two pieces of wood with V shaped grooves corresponding in angle to the rails. This forms the base of the easel AA. Make a frame 22 x 20, or rather larger than the biggest enlargement that it is desired to produce. It should be constructed of ½ in. wood, and be 2 in. deep. It is shown in Fig. 2 at 1 DDDD. Now make, or get made, a set of carriers EE, the largest of which should just fit into the frame. Narrow fillets of wood screwed each side will afford a rise and fall adjustment, and a thumb screw at G will fix the carrier in any desired position. To obtain the cross-movement screw the frame DDDD to a piece of inch board 5 in. wide HH. Place this exactly in the centre of the base board, and screw fillets II of 1 in. wood to each side. This will afford a cross motion, and a thumb screw at J will fix the carrier frame when the necessary adjustment has been made.
Fig. 2.