The Moving Picture World/Volume 1/Number 2/Lantern Slide Making
Before the Newton Health Camera Club, Mr. J. Taylor recently gave a very instructive address and demonstration of lantern slide making by contact, and we are indebted to the Photographic News for the following report report:
The lecturer, in his opening address remarked that, in his opinion, more photographers would take up slide making if they only knew how simple and fascinating the subject was. For the benefit of those members who had never made a lantern slide, Mr. Taylor briefly described the method of procedure as follows: The negative is placed in the printing frame film side up, and the lantern slide is placed emulsion side downwards in contact with the same. The exposure is then made in the same way as with bromide paper. The time of exposure varies with the make of the plate and strength of light; therefore, no hard and fast rule could be given. About 12 inches from an incandescent burner is a good distance to expose it. In the course of his remarks, the lecturer urged the necessity of thorough cleanliness in all the operations of slide making; he also recommended the backing of the lantern plate in all cases, as by this means much better results were obtained with a minimum of trouble. He also remarked that a lantern slide printing frame is to be preferred to the ordinary frame, as one is apt to scratch the films of valuable negatives with the edges of the slides when placing same in contact with the negatives. The lecturer then proceeded to expose several slides, and developed same in accordance with the following date, getting a fine range of tones, viz.:
| Solution A. | Solution B. | ||
| Water | 20 ozs. | Potassium bromide | 1 oz. |
| Sodium sulphate | 500 grs. | Water to | 10 ozs. |
| Hydroquinone | 80 grs. | ||
| Sodium carbonate | 500 grs. | ||
| Tone required. | Exposure. | Developer. | |
| Black | 15 seconds | 2 ozs. A | |
| Warm black | 30 seconds | 2 ozs. A and | 3 drops B |
| Brown | 60 seconds | 2 ozs. A and | 6 drops B |
| Warm browwn | 2 minutes | 2 ozs. A and | 12 drops B |
| Red brown | 4 minutes | 2 ozs. A and | 48 drops B |
| Red | 8 minutes | 2 ozs. A and | 48 drops B |
Exposure at 12 inches from incandescent burner, with an average negative.
In answer to a remark, Mr. Taylor said that an "average negative" was one that, when put on a sheet of fairly large print allowed of the reading being seen through the densest part of the negative.
With all lantern plates it is as well to thoroughly wash the same in running water after development, even if an acid fixing bath be used. The lecturer recommended the following acid fixing bath formula, viz.: Hypo, 4 ozs.; metabisulphite of potash, about 30 grs.; water, 1 pint—as by using an acid bath as it prevents stains on the slides. He also said that the plates should always be left in the fixing bath for 10 minutes to insure thorough fixing, afterward well washing for an hour in running water. When the lantern plates are thoroughly washed they should be wiped with a tuft of cotton wool while being held under the tap. This rids the plate of any deposit caused by the water, and the slide can then be dried. It is important that the slide he dried in a place where dust cannot get on same, as when it is placed in the lantern the dust is magnified and is very obvious. The simplest way is to put the plates about one inch apart on an ordinary plate rack and lay a clean sheet of paper over the top of them. The lecturer then went on to say that when dry the lantern plate has to be masked, mounted and spotted before it is ready for the lantern; for this purpose Mr. Taylor recommended the ruled masks, which can easily be cut to suit the subject, and at the same time they are provided with the white space for tilting and are already spotted, which saves some little time and trouble. He also showed how a lantern slide could be masked by means of the ordinary binding strips, and for this purpose recommended the use of a pair of compasses to insure getting the corners square. He strongly urged the members against using the ordinary ready-cut masks, which did not at all lend themselves to pictorial slide making.
Some magnificent results can be obtained by toning the slides in the hot hypo-alum bath, proceeding in a similar manner as when toning papers, except that the slides must be first hardened in a formaline bath; also any of the commercial toning baths for bromides, such as Velox re-developer, can be used for slide toning. Very fine tones can be got on lantern slides by means of the ordinary gold toning bath for P. O. P.
It is sometimes necessary to reduce a developed lantern slide which has been made too dense. The lecturer recommended the following: Potassium ferricyanide, 120 grains; water to 1 pint. To this, just before using, a dram or two of ordinary hypo-solution can be added. The template is immersed in the reducer when it is to be acted on all over; or, if it is only desired to reduce locally, the solution is applied with a tuft of cotton wool. The plate after reduction is well washed and dried.