925. Toning Slides

Toning Slides. The black tones which can be obtained with the formula just given are very fine, but for many subjects a warmer color is desirable, and this can be obtained by either toning or by the use of special plates, the image of which can be made warmer by simply increasing the exposure, and developing with a restrained developer. A great many lantern-slide makers follow this latter method, by which very fine colors indeed can be obtained.

926. The toning, by development process, has the advantage that the color is a pure one throughout the entire image. The color of the deep shadows is the same as the faintest deposit on the high-lights, which is not always the case when a slide is toned after development.

927. Developer For Black Tones

Developer For Black Tones. The following developing formula will give good results:

Stock Solution No. 1.

Pure Water ..............................

12

ozs.

Sulphite of Soda, Anhydrous..................

3

ozs.

Hydroquinon ..............................

75

grs.

Stock Solution No. 2.

Pure Water..................................

8

ozs.

Carbonate of Potassium......................

2

ozs.

Bromide of Potassium........................

15

grs.

To develop take of No. 1 Stock Solution, 3 ounces; of No. 2, two ounces.

928. Developer for Warm Tones.

Stock Solution No. 1.

Pure Water ..................................

8

ozs.

Hydroquinon.................................

25

grs.

Sulphite of Soda, Anhydrous..................

25

grs.

Bromide of Potassium........................

12

grs.

Citric Acid...................................

6

grs.

Stock Solution No. 2.

Pure Water.................................

8

ozs.

Carbonate of Soda, Anhydrous..............

240

grs.

To develop take equal parts. For still warmer tones it will be necessary to reduce the amount of Sulphite.

929. In making the exposure, for example, if it were to take two seconds exposure with a 16-candle power electric light for black tones, it would take three seconds for the warm tones. Bear in mind, that the resulting tone depends more upon the correctness of exposure; hence judgment and practice are necessary with the varying characters of negatives.

930. If there is any doubt as to the time of exposure required for a certain negative, the aim should be to underexpose rather than over-expose. A slightly under-exposed lantern-slide is always more satisfactory than an over-timed one, because of the distinctness of the image when thrown on the screen.

931. The temperature of the developers should be 70° to 75° Fahr. With the formulae just given, and the exposure correct, the time of development would be about three minutes for either the black or warm tones.

Note. - For further formulas of developers for lantern-plates, see Vol. II.