Colonel Stuart Wortley’s suggestion as to contributions of negatives would give a photographic exhibition, if adopted, a special technical interest; and we might in this include examples of negatives by the dry processes.
The question of retouching might be decided without difference of opinion by having two classes of works—one touched on the negative, and the other in which no touching other than stopping out pinholes should be permitted. If awards are made—and in this I recall Colonel Wortley’s mention of the medal of the Photographic Society—no award should be made for a touched negative unless a print from it before touching should be submitted to the judges at the same time, but not necessarily for exhibition.
It is clear that when we talk of excellence in photography we mean something other than what a draughtsman may do in the way of supplementing photography. Works which do not enter for an award may omit mention of the distinction I have indicated.
I believe that such an exhibition would excite a very general interest, and do more to improve the knowledge of photographers on practical details than years of casual acquaintance of what other men do.
I am, to a certain extent, an outsider, and cannot do more than suggest; but I hope that some of the influential masters of the camera will take up the question.—I am, yours, &c.,
W. J. Stillman.
100, Clarendon-road, Notting-hill, January 29, 1872.
NATURAL COLOURS IN PHOTOGRAPHY.
To the Editors.
Gentlemen,—Last night, as “I lay a-thinking,” the subject of obtaining photographic colour suddenly occurred to me, and the question arose as to whether the differences in the colours of the light reflected from the surfaces of different-coloured flowers (as red, blue, and yellow) was due to differences in the constitution of their juices, or of the solid matter of which they are formed. If on examination it proved to be of the juices, a second question arose as to whether it would not be possible to take advantage of this in the preparation of plates, as suggested by me in an article which you inserted in The British Journal of Photography for October 27, 1865 (No. 286, vol. xii.). Then, supposing that by this or any other means the three monochromic plates were obtainable, would coloured glasses placed in front of the lens help to stop off the colours not to be represented on the plate? Thus, with a plate sensitive to blue only, the interposition of a blue glass would prevent the transmission of the yellow and red rays, a red glass those of the blue and yellow rays, and a yellow glass that of the blue and red rays to the plates sensitive to the blue, red, and yellow rays respectively.
I have evidence that so early as 1842 the late Sir John Herschel obtained variously-coloured photographs on paper, as he gave me several, and I have still one a good blue, one a fair red, and two purple. The letter accompanying them describes the two latter as produced by the use of the juice of the red poppy; but many of them have faded away entirely. My impression is that others of them were from vegetable juices, but I am not sure that this was the case. There can be no doubt, however, that his published papers will give an account of the numerous experiments he made on this subject.