DEVELOPING THE PLATE.
For this purpose we have the choice of numerous formulas in which the acting developing agents are pyrogallic acid or hydrochinon. Of these for our first lesson we will take the hydrochinon, as that offers less difficulties for the beginner. Before closing the door of our dark-room we will mix the developing solution. The following formula is easily prepared, and we have always found it to work well: Hydrochinon, 25 grains.
Sulphite soda crystals, 125 grains.
Carbonate soda crystals, 125 grains.
Phosphate soda granular, 60 grains.
Water, to make 4 ounces.
To prepare this, we take first from our stock solution of sul phite of soda twelve and one-half drams, which gives us 125 grains; we then measure out twelve and one-half drams carbon ate soda and six drams of phosphate soda, which we add to the sulphite soda, and add water to make the whole up to four ounces. We pour this into a clean bottle, in which, after care fully weighing, we pour twenty-five grains of hydrochinon. We cork the bottle, and shake it occasionally for ten or fifteen min utes when it will be ready for use.
This developer, which is the same as our formula II. (chapter 3Z XII) made here in one solution, we give simply as an illustra tion of the manner of preparing it fresh. It will be more con .
venient to make it as in the formula in two solutions, which will allow you then to add more or less of either No. 1 or No. 2, as needed to produce intensity or detail. The hydrochinon pre vared as described in two solutions, will keep fresh for months.
We now prepare the fixing solution by pouring two ounces of our stock solution of hyposulphite soda into the japanned tray, to which we add two ounces of water, or simply use four ounces of g' filtered hypo," if prepared as previously described. We use a black tray for the fixer so that we shall never be liable to mistake it for one of the developing trays. On no account must this tray be used for anything else. It must always be reserved for the hypo., and no drop of that must ever be allowed to get into the regular developing tray. Remember always to use plenty of irxer, entirely covering the plate.
Before closing the door and getting a plate ready for develop ment, we very carefully wash out the one or two glass graduates which we have been using to mix our solution. We wash them immediately, because it is so much easier to clean them before the few drops of solution remaining in the glasses have time to dry. It is a good plan to wash thoroughly every graduate and funnel or tray immediately after using it, remembering always that it is not possible to keep these too clean, and that we are very likely to have trouble in some part of our developing or toning if we do not use perfectly clean glasses. We will now close the door and light our dark-lantern. N otice that there is no other light in the room beside the feeble light given by our dark-lantern, and when this light is out the room is absolutely dark. A ray of daylight
or gas or lamp-light in the room might instantly ruin the plate. As these plates which we are going to develop are slow plates, we shall develop them in all the light that our dark-lantern will give us, and we especially do this now so that all the processes can be distinctly seen. If the plates were quicker, or of a much higher sensitometer, and therefore more sensitive to the light, we should carry on most of the development at some distance from the dark-lantern where the light would be very weak, or else shield them from the light by placing a cover of dark paper over the tray during the development, examining the plates under the brighter light for a few seconds at a time to see how the develop ment was working. Having everything ready, we now take one of the 5 x 8 plates from our plate-holder, and carefully go over it with a soft brush to remove any particles of dust which may have settled upon the film during or after the exposure. This brush must be kept always free from dust and moisture, and in a clean place. The plate being carefully dusted, we lay it, the film side up, in the tray, which we immediately rock to make the solution flow over every portion of the plate. If we notice that any air bubbles in the solution adhere to the film we must touch them at once with a fine, soft brush or with the finger. Should we not do this the bubble would prevent the developer from acting on that particular spot, and this would show as a transparent spot after fixing. We rock the tray slowly by gently raising one end and then the other to allow the solution to flow back and forth over the plate. After the plate has been in the solution twenty-five or thirty seconds the picture slowly begins to appear. First the portions of the picture that were the brightest, or the high lights as they are called; that is, first the sky, and then any water which may reflect the sky and so appear bright, and then the lighter portions of the picture. After that follows the foliage, the fore ground, and, lastly, the shaded parts; we continue the develop ment until we are able to see some details clearly in the shadows, and also until the picture which had come out clearly begins to fade away. If we cannot judge of the intensity, nor see the details with sufficient clearness in the tray, the plate can be taken up and examined by looking through it at the light of the dark lantern. With the first dozen or so plates we shall have to use considerable guess-work to know when the development is com plete. But after a little experience we shall manage this without any trouble. The plate being now developed, we have to wash it before placing it in the fixer which we have already prepared.