Motography (Apr-Dec 1911)

November, 1911. MOTOGRAPHY 219 process the negative may be anything from 4 by 5 to 10 by 12, the size being limited principally by the cost of the plates and camera. A brief sketch of the four-tray method of development will be given here for the benefit of those who desire to develop their negatives in the dark room rather than by means of the tank. A word of warning may be in place here regarding the usual method employed by most amateurs, wherein the plate is immersed directly in a full-strength developer without regard to its exposure. On absolutely correct exposures this plan may give good results ; but how many of us are sure that our exposures are even approximately correct? The four-tray plan gives considerable latitude in the matter of exposures, and its use is strongly recommended. For this method we employ four trays, A, B, C, and D. In A is placed the developer made full strength according to formula; in B a half-strength solution of the developer is poured, — that is, a solution containing just twice the normal amount of water ; C contains the restrainer which is made by adding a few drops of a ten per cent solution of bromide of potassium to the tray of water ; and in D we place clear water. In use, the four trays are manipulated as follows : Let us suppose that we have three plates, which have received varying exposures. We will call these plates 1, 2, and 3 respectively. We will place Plate 1 in tray B, which contains the half-strength solution of developer. If the image appears in forty-five or fifty seconds, the exposure has been approximately correct, and the plate may be left in that solution or transferred to the full strength developer in A, to finish and attain the desired density. Taking Plate 2, we place it in B. If the image appears very slowly, indicating under-exposure, the plate should be left in Tray B until the high lights are faintly defined. It should then be quickly transferred to Tray D, containing clear water, without previous washing. An examination of the plate half an hour later will show considerable detail in the shadows without any great increase in the density of the high lights. The plate will probably have sufficient detail at the end of this time to warrant its being transferred to Tray B, in which the density will gradually be increased. In the case of Plate 3, we will suppose that the image appears very quickly after the immersion in Tray B. This will indicate over-exposure, and the plate should be transferred to Tray C, containing the bromide of potassium. After remaining in the restrainer for two minutes, the plate may be replaced in Tray B, where it may remain, unless the image continues to appear too quickly, when it should have a further session in the restrainer. Remember, that the flatness and weakness of an over-exposed plate is due largely to under-development, and the plate should therefore be left in the developer for a couple of minutes after the plate blackens, before placing it in the hypo. In every case the plate should first be placed in Tray B, until its symptoms have appeared. The illustrations show some useful adjuncts to the printing room. These articles will be described in detail, as they will be frequently referred to in later instalments of this series. The printing frame shown in Fig. 1 is one of the most useful the author has had occasion to use. These frames are now on the market in the form illustrated, or one may readily be made at home. The stock necessary for the construction consists of two pieces of whitewood, 8x10 inches. The under piece may be of %-inch stock, while the upper may be ^2 inch thick. In the upper piece, B, an opening is cut to take a lantern-slide plate. The edges of this opening are, preferably, but not necessarily, made tapering, with a smaller dimension of 3}4 by 4 inches. This will assure the slide plate being in just the correct position in the holder, and will facilitate its removal after printing. The cover, which fits the opening, is hinged and fastened with a button, as shown. The piece, B, is covered on its lower side with thin felt, and the cover, A, should be covered with a somewhat heavier layer of felt. The lower piece, C, has an opening in it which coincides with the one in B when the latter is closed upon it. The piece B is hinged to C at the end. The surface of C is covered with heavy felt where it comes in contact with that on B. The lower side of C is recessed, as shown in Fig. 2, to take a 4 by 5 plate, the use of which will be explained in due time. In use, the negative is laid with its emulsion side up on the surface of C in such a manner that the light will pass through that part of negative which it is desired to print on the slide. The piece B is then clamped down by means of hooks, as shown, and the slide plate is placed in the opening, with its sensitive side in contact with the emulsion of the negative. ' ' fi Fig-. 4. Elxposure Board for Multiple Printing. For intelligent and systematic printing, the device shown in Fig. 3 should be used. This is merely a board, some three or four feet in length, on which is arranged a stand for the printing frame. The edge of the board is graduated -'into inches, which should be measured from the surface of the slide plate to the point of light. The construction is clearly shown in the drawing, and no further comment is necessary. The choice of a printing light will depend upon the individual. In the author's opinion, there is nothing to equal electric light for the purpose, as it is so easily controlled. If the house is not wired for electric lights, a small tungsten lamp, such as are sold for train lighting, may be used, and as it is in use for so short a period of time, the current can be supplied by a battery of dry cells. The quality of the light produced by a tungsten lamp renders it peculiarly well adapted to the purpose. The convenience of such an arrangement will be better understood when it is said that the printing may readily be done right in the dark room and the exposure is made by turning on a switch instead of uncovering the light. Care must, of course, be used to see that there are no boxes of plates left uncovered in