The Dictionary Of Photography

A True Historic Record Of The Art & Practice Of Photography 100 Years Ago.

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camera, focus carefully, and, marking two prominent objects on the edges of the screen, adjust the small view-meter till the same objects are exactly on the edges of the field of view in that. Now mark on the inner sliding tube with a knife or file the exact point to which it was pulled out or in, and this will always include the amount of view included by that lens. By
Fig. 126.
fastening two fine wires across the cap p, as shown by the dotted lines, it will serve well also as a view-finder, as, when the moving object is at the point of intersection of the crossed wires, it will be in the centre of the plate. It may also be used as some guide to the probable exposure by placing inside the cap a circle of blue glass, so as to cut off the rays which are more especially chemically active.
Vignetting. This consists of shading off the margins of a picture, so as to cause the figure or subject to gradually fade away. There are numerous methods of effecting this : one is by the use of glass with oval or other shaped openings surrounded by a gradually deepening margin of coloured non-actinic glass. These, however, are not satisfactory. Another method is that employed by the French operators of using graduated thicknesses of tissue paper with serrated edges. Another method is to use wooden covers with openings having the underneath edges bevelled off. But the best of all is to use stout sheet lead or pure tinfoil, and to cut the sized opening required, and either to slightly turn up the edges or serrate them, so as to soften the outline; and the farther the vignetting shape is placed from the negative the larger the vignette and the softer the outline,