This section is from the book "Modern Photography In Theory And Practice", by By Henry G. Abbott. Also available from Amazon: Modern photography in theory and practice: A hand book for the amateur.
We have now made two exposures, or taken two pictures, one of a yacht and the other a wood scene with water for a foreground. It will not do to keep on recklessly exposing plates without knowing what we are doing, so we think it advisable to develop these two before going further.
Up to the present time we have no dark room, and we do not think it advisable to build one until we know better what is required, and so we will develop these two plates in the same room in which we loaded our plate holders, taking the same precautions about shutting out all light. Of the various developers and their action we will speak later, but in this instance we will use the developer recommended by the Seed Dry Plate Company, who made the plate which we are about to develop. The second plate was made by the Stanley Dry Plate Company, and it would hardly be advisable to mix up two different developers to develop only two plates, because the same developer will answer for both plates. As a rule, however, it will be found advisable to use the developer recommended by the plate makers. They know the chemical constituents of their plates and are better able to judge which is the best developer for their own plates.
We shall need the following trays and adjuncts, and they will all be transferred to our dark room when we build it: Two 4 1/2 x 5 1/2 developing trays; one 7x9 rinsing tray; one fixing bath; one combined washing and drying rack; one 2-inch camel's hair brush; one minim graduate glass; one four-ounce glass graduate and bottles for your stock solutions of developer and other chemicals. You will also require a pair of scales, a glass funnel, two glass rods, and some filter paper.
Fig. 14 illustrates a developing tray. These trays are made of hard rubber, fibre, celluloid, papier mache and tin. We should advise the selection of hard rubber or compressed fibre trays for developing, while a papier mache or tin tray will do very well at the start for rinsing purposes. For the present the fixing might be done in a tray or shallow dish, but as you will want a regular fixing box sooner or later you might just as well purchase it at the start. A very good form of box is shown in Fig. 15, as in using it your fingers need not come in contact with the solution, either in putting the plates in or taking them out of the bath. A false bottom is connected to a central rod and the plates can be lifted out clear of the solution. In selecting trays, never get one with a plain or smooth bottom, but select the variety which has grooves or projections on the bottom. The plate adheres to the bottom of a smooth tray and is often very hard to lift out. The grooves or projections on the bottom allow you to place your ringer or the lifter under the plate. Fig. 16 illustrates a lifter, which is made of hard rubber and which will be found very useful for lifting plates out of the trays. They are quite inexpensive and every photographer can afford to have two or three of them, so they will be handy when wanted. Fig. 17 illustrates a combined washing and drying rack. The plates are first washed in this rack and then taken from the water and laid aside to dry. The tray at the bottom being water tight, catches the drippings from the drying plates, which is a very desirable feature. When the plates are dried and removed, the sides can be folded down into the tray and it occupies but little space. Fig. 18 illustrates a four ounce glass, graduate, which you will need when measuring the larger quantities of liquids, while the minim or smaller graduate is used for measuring the smaller quantity. In selecting a funnel be sure and buy one of glass, of the fluted variety, as shown in Fig. 19. A glass funnel can be kept perfectly clean and the fluted variety works much more rapidly than the ordinary funnels when filtering, as the fluted portions allow the air to circulate between the funnel and the filter paper.
Having now secured the requisite chemicals for developer and fixing bath, as given by the plate maker, we are ready for development. Our developing solution is ready in our four ounce graduate, water in the rinsing tray and hypo in our fixing bath. We shall also require a pail full of clean water and a towel on which to dry our hands. All being in readiness we shall proceed with our development. We draw the rubber slide from our plate holder and remove the plate as heretofore described. With the camel's hair brush we remove any particles of dust that possibly may have rested on the plate since it was taken. We now place the plate in one of the 4 1/2 x 5 1/2 trays with the film or sensitive side up and pour the developer over it, gently rocking the tray in the meantime to insure that the solution covers the plate entirely. Keep your tray constantly rocking and look out for air bubbles on the plate, par-ticularly in warm weather. Should there be any, break them by means of the finger tips or a camel's hair brush. If you allow them to remain they will prevent the developer reaching that portion of the plate and a flaw will be the result.
When the plate was placed in the tray there was no trace of an image upon it, but very soon, if it is a properly timed negative, you will observe that the negative darkens in spots. Do not bring the tray too close to the light, especially during the early stages of development. Our negative consists almost entirely of sky and water and it should come up very evenly all over. If it were a landscape the sky would darken first. In other words, the light portions of the picture darken first and then the half-tones and finally the dark portions or shadows are darkened.
The Seed Dry Plate Co., recommend the following Pyro developer:
Distilled or good well water...16 ozs. Sulphite of soda (Crystals)... 4 ozs.
Pyrogallic acid................. 1 oz.
Sulphuric acid ................10 drops.
Sal soda (crystals).............. 4 ozs
To develop with this solution take one ounce of No. 1 and one ounce of No. 2, and add to it eight ounces of water. Use less water in cold weather. Now the constituents of the developer are pyrogallic acid, commonly known as Pyro, which is the developing agent proper, sulphite of soda, which is a preservative and is used to keep the solution clear and bright, and sal soda, which is an accelerator, or agent which makes the developer act quickly. Make a solution of one ounce of bromide of potassium in ten ounces of water and keep it in a separate bottle, and when it is found that the developer is working too rapidly, owing to the plate being overexposed, a few drops of this solution is added, which holds back development and is known as a restrainer. This is known as a ten per cent solution of bromide. We now know the constituents of our developer and how the various chemicals act, and we can govern ourselves accordingly.
We have now reached a critical stage in our develop-ment. How long, or how far shall we carry our development? On this depends entirely the success of our picture. If we develop too rapidly the half-tones are lost and if we carry the development too long we will get a flat, muddy negative which has no contrasts. Various methods are pursued by photographers, both amateur and professional. Our method is to keep the plate in the solution until the image has shown fairly strong all over. Now remove the plate from the solution, by means of the lifter shown in Fig. 16, and holding it by the edge, bring it close up to the light and look through it in order to see how far the development has progressed in the shadows and half-tones. Keep your lingers off the film and hold the plate by its edges by pressing against the glass on both sides. If a 4 x 5 plate you can readily hold it in one hand by placing the thumb on one side and the forefinger on the other. Bear in mind that all portions of the negative which have received the black deposit will print white or light in tone, while those portions of the plate which remain white will in reality print black, because the light passes through the clear glass of the negative and prints the paper dark. Now turn the plate over or look at the other side, not through the plate, but by holding it in a horizontal position, and see if the image is beginning to show through the plate. If it is, the development is nearing completion. Return the plate to the solution and continue rocking, examining it from time to time. In a properly timed negative the image should begin to appear on the film side in from 15 to 30 seconds. There is a scientific method of determining when the development has reached the finished stage, but this method we will discuss later.
We continue the rocking of the plate until, in the subdued light of the dark room the entire plate has blackened over. Examine it again by transmitted light and you will see the outline very faintly. Look at the back of the plate and you will see the outlines of highlights and the principal half-tones. Holding the film side towards us and the glass side well up to the ruby glass, we place our finger on the glass back of the sky and find the deposit is so dense we can scarcely see the shadow of our finger.
We now rinse the plate thoroughly in the rinsing tray, in order to remove the developer and small portions of the film which have separated from the plate. This rinsing prevents the contamination of the fixing bath. Our fixing bath, which has previously been prepared, is also in accordance with the Seed formula, which comes with every box of plates. Our plate, after washing, is inserted in the fixing box, shown in Fig. 15. The ama-teur at this stage usually makes two mistakes, he does not fix his plates thoroughly and more often does not wash them sufficiently to remove the hypo. The plate should be allowed to remain in the fixing bath fully ten minutes after every trace of the white film has been removed and must only be examined by white light when this stage has arrived.
When properly fixed the plate is inserted in the combined washing and drying rack shown in Fig. 17, and the rack placed in the pail of water. The pail may now be taken out of the room and placed in a sink and the water allowed to run into the pail for at least one hour, in a gentle stream about the size of an ordinary lead pencil. Do not allow the stream to strike the plate, but have it go down one side of the pail. It is very essential to thoroughly wash your plates to remove the hypo or they will soon turn yellow and become covered with the hypo salts which will eat away the film. When sufficiently washed remove the rack from the pail, emptying out the water in the tray under the plate and put it away to dry in a place free from dust. Do not attempt to dry the plate in the sun or by artificial heat.
While the first plate is being fixed in the hypo bath, we proceed with the development of the second plate, which we proceed with on the same lines as the first.