Chapter VIII: Enlarging at Home—daylight

For many pictorial and decorative purposes the amateur will experience the need of a simple method of producing large pictures from his small negatives. This brings us to enlarging on bromide paper as among the things which may be easily and profitably done at home by daylight or artificial light. For daylight enlarging no special apparatus is needed, beyond the camera and lens used to make the original negative, and a couple of large trays for the development and fixing of the enlargement. Presuming that we do not intend an enlargement larger than 10 x 12 inches, these latter may be of vulcanite or japanned tin, and inexpensive.

To begin we require a small room to ourselves, with a window facing north, and giving us an unobstructed view of the sky. This window we make absolutely dark by fitting to it a light wooden framework covered with black cloth, or two thicknesses of brown paper. The room is now quite dark, and we must work by gaslight until we are ready to enlarge. In the window shutter, at a convenient height, we cut an opening exactly the size of the negative to be enlarged. At the two sides and bottom of this opening we glue three wooden laths, and fasten a drawing pin in each, so that we can slide our negative in, upside down, and it will be held close to the opening. The film side of the negative must always face the back of the lens. Outside the window we place a sheet of white cardboard, or a mirror, at an angle of 45°, so that it will help us to throw as much light as possible through the negative at the opening in the shutter.

Returning indoors, we place a long table with one end close up to the window, and on it place a box of such a size that, when we place our camera on the box with the lens pointing into the room, the back of the camera (ground-glass removed) exactly covers the frame enclosing our negative. The light reflected by the cardboard outside now streams into the room, passing through the negative, camera, and lens. At the other end of the table we place a box on its end, and take care that it shall be perfectly upright. To the front of this box, facing the lens, we pin a sheet of white paper measuring about 11 x 14 inches. The image of the negative in the window appears (upright) upon this white screen. By moving the box nearer to or farther away from the lens we get the enlarged image of the desired size, 10 x 12 inches, but it is not sharp, _i.e._, its details are not clearly and distinctly defined. By means of the focusing front of the camera, or by moving the box a little back or forward, we gradually get the enlarged picture of the right size and perfectly sharp; in other words we focus it correctly. The brightness or illumination of the image depends upon the intensity of the light outdoors, and the diaphragm used in the lens. We must use as large a diaphragm as we dare, consistent with the desired degree of sharpness in the picture. If the image is not equally sharp all over, we must see whether the front of the box carrying the sheet of paper is perfectly parallel with the negative. This is essential. Another detail to be looked after is to make sure that no light enters the room save through the camera and lens. When we have got all these preliminaries arranged to our satisfaction we are ready for the actual work of enlarging on bromide paper, and from now on must work by the light of our dark-room lamp.

What is bromide paper? It is simply paper coated with a sensitive emulsion, exactly like that which, coated on glass, forms the sensitive dry plate used in making negatives. The emulsion on bromide paper, however, is much less rapid than that used in making plates. Thus we must handle bromide paper with all the care used in handling sensitive plates before exposure, and scrupulously keep it from white light until it has been exposed, developed, and fixed. Its manipulation is precisely similar to that employed in making negatives, but the character of the support (white paper) indicates that we must be more careful in the matter of cleanliness in our manipulation of paper than with plates.

Covering the lens, and working by the dim red light of the dark-room lamp, we open the package of bromide paper and take out a single sheet, which we cut into strips one and a half inches in width and the full length of the sheet. These we will use in making test exposures to ascertain the correct exposure for our enlargement from the negative in hand. To make a test, pin one of the strips to the cardboard or sheet of paper on which the image was focused, in such a direction that it includes part of the shadows in the picture. Now cover three-quarters of the strip with a piece of brown or black paper and (supposing that we have bright light outdoors, a negative of medium density, and stop _f_/16 in the lens) give the quarter of the test strip an exposure of one-half minute. Cap the lens, uncover another quarter of the strip, and give it an exposure of another half minute. Repeat this operation with the remaining two quarters of the test strip, and replace the cap on the lens. We now have a strip which has received four different exposures. The first quarter of the strip has had two minutes exposure; the second quarter, one and a half minutes; the third, one minute; and the fourth quarter, one-half minute. Upon developing this test strip in the developer yet to be given, we will be able to judge as to the correct exposure required, to get a good enlargement. Very thin negatives will sometimes require only ten to thirty seconds; negatives of medium density from one-half to one and a half minutes; very dense negatives from one and a half to several minutes; after a little experience we will find ourselves able to judge the exposure required by the appearance of the negative on the screen.

When once we have determined the correct exposure for an enlargement from any particular negative, and have _also_ taken the _actinometer time_ of the light by exposing our Wynne meter at the opening in the window through which the light enters, we can obviate any difficulty in making other daylight enlargements from this negative by marking on the edge of the negative the exposure time and the actinometer time. Thus suppose the time of correct exposure was fifteen seconds, and the actinometer time was only six seconds, we mark the negative 15 _Ex_/6 Act. If we divide the correct exposure time by the actinometer time we get two and one-half as the result. Then we know that, for all after enlargements of the same size from that negative, on the same brand of bromide paper, the exposure should be two and one-half times the actinometer time. After a few negatives have been tested and noted in this way we will be able to intelligently compare other negatives with these tested ones and judge, approximately, of the exposure they will require without the necessity for a special test with each and every negative.

Having determined the correct exposure required by the negative in hand, we return to the darkened room and pin upon the white card opposite the lens a full sheet of bromide paper, uncover the lens, and make the exposure. The lens is then covered, and the exposed print is removed from its support, enclosed in a light-tight envelope or tube, and taken into the dark-room for development.

It is agreed that next to ferrous oxalate (which we will not trouble with) a combination of metol and hydroquinone gives the best developer for bromide paper. An excellent formula, originated by Yellott, is as follows: Dissolve 55 grains of metol and 55 grains of hydroquinone in 40 ounces of water; add sodium sulphite, 2 ounces, and sodium carbonate, 2 ounces. This forms a one-solution developer which may be prepared some time before it is needed, and stored in 2-ounce bottles carefully corked. Two ounces of this solution gives us a sufficient quantity of developer for an enlargement not larger than 11 x 14 inches. Just before use the contents of one bottle should be diluted by adding from two to four ounces of water, and three or four drops of a ten per cent solution of potassium bromide. This developer can be used repeatedly, but if it is used too often will give greenish-black tones. Care must be used not to add too much potassium bromide; too little will result in degraded whites, and the print will acquire a foggy appearance; too much will give unsatisfactory tones. What we must seek to obtain is a rich black tone, like that of a good platinotype print. Amidol, citol, rodinal are other good developers for bromide paper.

To develop the enlargement, lay the print, face up, in an 11 x 14 tray and flood it with water for a few moments to prevent it curling; pour off the water and with a steady, even motion, flow the diluted developing solution over the whole of the print. In a few seconds the image will appear and gradually increase in detail and density. As soon as it reaches the desired strength, pour the developer off into an empty bottle (labelled _Used Developer_), rinse the print in running water and immerse it in the fixing bath. This latter should be freshly made by dissolving sodium hyposulphite, 3 ounces, in water, 16 ounces. In this the print should be quietly rocked for ten or twelve minutes, after which it should be removed and thoroughly washed for an hour and a half in running water.