Early Work In Photography
A Text-book For Beginners

20 Early Work in Photography. wards, and cover it with a sheet of sensitive paper-sensi- tive side downwards, i.e. in contact with the film side of tlie negative. Then replace the back of the printing frame, and expose the glass side to strong daylight. At the end of about ten minutes the frame may be removed to a weaker light and one half of the picture examined, when the use of a negative in producing a positive image will at once be apparent. If printing has not been carried far enough, in other words if the photogram does not appear to be several shades darker than required, the frame must again be closed (care being observed to avoid moving either negative or print, during the operation), and again exposed to dayliglit. There is no rule whereby the time of exposure can be accurately determined; all depends upon the quality of the negative, and the actinic* power of the light. For instance, if the negative be a dense one, more exposure must be allowed than if it be a soft one, full of delicate gradations. Again, if the sensitive paper is exposed to sunlight, the action will necessarily take place more rapidly than on ex- posure to diffused daylight. The light during the winter season is also much less powerful than of springtime or summer. All these matters tend to govern the time of ex- posure, hence the necessity of examining the course of the printing at frequent intervals. As a rule it is advisable that the printing be carried on until the deep shades are more vigorous than will be desired in the finished photogram, and the white portions are ap- preciably tinged with colour. When the student is able to secure the same effects (from one negative) half-a-dozen times consecutively, he may ven- ture to try some experiments in printing medallions and vignettes. And here we must again impress upon the student that our object is to make him feel quite conversant with the method of printing from, and handling, a negative before dealing with the more complex matter of making one. In order to produce the so-called “medallion ” prints, we shall require a packet of masks and discs (| plate size), pro- curable of any stock-dealer. These masks are made of black paper, pierced with various sized openings in ovals, squares, and other shapes, and they are used as follows: The negative is supported (film ide upwards) upon a sheet of glass in the printing frame in the usual way, but, instead of then placing a sheet of sensitive paper directly in contact with it, we must first cover it with a black paper mask, * See Glossary.