PHOTOGRAPHIC CORRESPONDENCE.
Photographic Slides for the Magic Lantern.—Might not the collodion process be applied very usefully in the preparation of slides for the magic lantern?
Good slides are always expensive, owing, in great measure, to the accuracy required, where every defect will be magnified some hundred times.
I would suggest that a photographic picture should be taken on the glass plate, and then varnished. The painter should then apply his colours to the opposite side of the glass, using the photographic image as his outline. The colours would then be burnt in, and the varnish and collodion film cleared off.
This plan would be especially useful when the photographic picture had been taken by the microscope.
Thos. Scott, B.A.
Brighton.
Albumenized Paper.—If Mr. Hele will follow the directions contained in a paper of mine which you published in Vol. ix., p. 206., for albumenizing paper, I think he will have no reason to complain of waves, or streaks, or blotches, and will be saved the trouble of the damping process which he uses and recommends to others. ("N. & Q.," Vol. ix., p. 254.) I have done a considerable quantity of paper of Canson, both positive and negative, and also of other makers, Whatman, Turner, Sandford, and Nash, and in all I have succeeded perfectly in obtaining an even coating of albumen. I am convinced from my own experience that the cause of waviness, &c., is due to raising the paper from the albumen too slowly. If the paper be snatched hastily from the solution, air bubbles no doubt will be formed; but if the paper be raised with a steady even motion, not too slow, the albumen will flow evenly from the paper, and it will dry with a perfectly even surface.
Mr. Shadbolt is certainly mistaken in saying that positives printed from negatives will not stand a saturated solution of hypo. soda, unless they be printed so intensely dark that all traces of a picture by reflected light are obliterated. I have used nothing but a saturated solution for fixing my positives for a considerable time, and my experience agrees with that of other of your correspondents, that the picture is not as much reduced by a saturated solution as by a weaker one. By adding about one grain of sel d'or to every eight ounces of saturated solution, very rich black tones will be obtained.
I inclose a specimen of what I have got in this way.
C. E. F.
[The specimen sent is most satisfactory; we wish that the locality of the view had been stated.—Ed.]
Mounting Positives on Cardboard.—In the absence of any other reply to J. L. S. (Vol. ix., p. 282.), the following, as the method I always adopt, may serve his purpose.
Having cut the positive to the size required, and trimmed the edges, place it upon the cardboard to which it is intended to be attached, and carefully centre it; then with a pencil make a slight dot at each of the angles. Remove the proof, and lay it face downwards upon a piece of clean paper or a cloth, and with any convenient brush smear it evenly over with a paste made of arrowroot, taking care not to have more than just enough to cover it without leaving any patches. Place it gently on the cardboard, holding it for the purpose by two opposite angles, and with a silk handkerchief dab it gently, beginning in the middle, and work any little superfluity of the paste towards the edges, when it will be gradually pressed out. The whole may be placed in a press, or under a pile of books to dry.
My object in using arrowroot is simply that of having a pure starch without colour, and it serves as a size to the paper, which has lost that originally in it by the repeated washings, &c.
The paste is made very thin, thus:—Put a teaspoonful of arrowroot (not heaped) into a teacup with about two spoonfuls of cold water, and mix into a paste: then add boiling water enough to fill the cup, and stir. Many photographers merely attach the edges of their pictures, but I prefer them to adhere all over. Gum is fatal to the beauty of a photograph, unless it is previously re-sized.
Geo. Shadbolt.
Mr. Lyte's Collodion (Vol. ix., p. 225.).—Our readers may remember that in "N. & Q.," Feb. 18, Mr. F. Maxwell Lyte furnished our readers with a detailed plan of his mode of preparing collodion. In that article, written from Pau, that gentleman was so good as to promise us that when he had an opportunity he would send us a couple of specimens of his workmanship. He has more than fulfilled his promise, for we have received from him this week four photographs, which, for general beauty and minuteness of detail, cannot be surpassed. The subjects are, I. Study of Trees, No. 2.; II. Study of Trees, No. 5. Old Pollard Oak; III. Study of Trees, Peasants collecting Leaves; IV. Old Church Porch, Morlâas, Monogram of the Eleventh Century. Mr. Lyte, who is a first-rate chemist, has shown himself by these specimens to be also a first-rate practical photographer. From him, therefore, the art may look for much future progress.