The Optical Magic Lantern Journal (August 1898)

The Optical Magic Lantern Journal and Photographic Enlarger. 117 of 121, Shaftesbury Avenue, London, W.C., are not only supplying the apparatus of which we have spoken, but they also supply apparatus Fig. V. for taking and viewing these pictures-in-colour stereoscopically ; the instrument for viewing | them, Fig. V., being rot unlike an ordinary table | stereoscope. == OH How to Make Lantern Slides. By WALTER S. KAYE. (Prise Article, ‘ Photo-American.'') SV @eSX\ O much has been published on this interesting branch of photography | Say as large as 5 by 7. ; In passing to the negative. | dentists) about 2 inches wide. that the writer ventures with diffi| dence on the field. He is encouraged to do so only by the hope that ; t 3) founded upon his own experience may . clear from the path of others some of | the difficulties which have beset his own. | A lantern slide is a positive on glass made | from a negative, used for illustrating lectures or other entertainments by means of a magic lantern or stereopticon giving an enlarged reproduction upon a screen. The slides are made in different ways—by the wet collodion, carbon | and printing-out processes, by reduction in the camera, by contact, etc. In this paper I will | discuss the contact method. The necessary articles are a box of lantern plates, a deep printing frame, a ruby light, a stock of developer, two trays, hyposulphite of soda, a washing box and a negative drying rack. If gas is used for white light, have a burner that can be lit and put out by turning a lever. Chain pulls for operating lights are not desirable, as the operator is apt to pull the wrong chain and spoil the slide by over-exposure. The lever the following homely observations | ‘as the plate), film side down. is free from this objection and gives the operator full control of his light. The lantern plates made in this country are practically all of the same dimensions, 34 by 4 inches. Abroad they are a smaller size, 3} by 3}. I prefer Carbutt’s plates, having found them more uniformly reliable. The printing frame should be at least 8 by 10 if it is desired to make slides from negatives, The smaller negatives, 87 by 4} or 4 by 5 are, however, generally used. The negative being larger than the lantern plate, only a part of it can be taken by contact. Absolute certainty of getting the positive in the centre of the plate may be insured by the following procedure :— Take a piece of smooth, flat board (wood) 8 by 104; cut from the centre a square hole 3 by 3 and bevel the edges of the four sides so that they will not obstruct or reflect the light On the side of the board opposite to that which is bevelled, glue to within one-eighth of an inch of the hole a strip of rubber cloth (such as that used by This is to prevent the negative from slipping. Next take a piece of cardboard 8 by 10, a little thicker than a lantern plate, and cut from the centre a rectangular hole 33 by 4. A pad of black felt or velvet 4 by 5 completes this part of the equipment. Put the 8 by 10 bevelled board in the printing frame bevel side down ; then place the negative over the hole, film side up; next pick up the frame, keeping the negative in place with the thumbs, and hold it toward the light. The negative can now be worked around in any direction until the desired part is brought to the centre. When this is done, lay the frame down, being careful not to disturb the adjustment, and drop in the 8 by 10 cardboard. The operator can now turn out the white light and take a plate from the box. This he should dust carefully with a soft, camel-hair brush, and slip into the rectangular opening in the cardboard (which, it will be observed, is of the same dimensions Over this place the pad of black felt or velvet and put in the back of the printing frame. We are now ready for the exposure. Plates should always be exposed a known distance from the light. I have seen lately a handy device for this purpose in the shape of a string tied to the bottom of the burner, having a knot every foot for three or four feet. By picking up the string you can slip along as many