A Manual Of Photography

GENERAL REMARKS ON THE USE OF THE CAMERA OBSCURA. 301 obtain a very perfect definition of outline. Many productions are remarkable for this, and, indeed, reproduce with unnatural exactness all the minute details of the objects copied; whereas the human eye never sees this extraordinary sharpness of outline in nature ; upon the edge of every object there are fringes of light which soften off their outlines, and subdue the general tone of objects, blending all harmoniously. Per- haps there is more than ordinary difficulty in producing this in a representation of nature which is effected by means of a lens. The artist may, however, do much: al1 times, even of bright illumination, are not fitted for producing a pictu- resque photograph. Nature should therefore be looked at with an artist's eye, and the happy moment chosen when the arrangements of light and shade give the most picturesque effects, and when these are in a condition to be correctly reproduced according to the laws by which actinic influences are regulated. Section II.—Portraits from the Life. It is important for the production of a correct likeness that as small an aperture as possible should be used. By doing this there is great loss of light, and consequently the necessarily pro- longed time must be compensated for by greatly increased sensibility in the plates. It is also important that arrangements should be made to cut off from the lens al1 light proceeding from extraneous objects: this is best effected by the modes adopted by M. Claudet. 81. The camera is placed, as shewn in section, Big. 81, within an arrangement of curtains which, as will be seen in the vignette heading to this part, page 187, is capable of adjustment, so as