202. Cutting Films

Cutting Films. It is sometimes found preferable to cut the film up into the individual exposures before development. In this case you must exercise care in unrolling the film, so that the film does not roll up over the paper. The exposures should be cut apart with the paper on top. Cut by the marks appearing midway between the figures in the center of the black paper. In cutting Panoram films, follow the special instructions given in the manual accompanying the Panoram camera. Proceed to develop the individual films, according to the directions for developing the roll of film, keeping the face side of the film down, in order to prevent curling.

203. Rinsing Films

Rinsing Films. When the films are developed rinse them in three changes of water, and then pass them into the acid fixing bath. This can be made up from the perpared fixing powders, which only call for the addition of water; or by the student himself, according to the following formula:

204. Formula for Acid Fixing Bath.

Water................

16 ounces

Hyposulphite of soda.............

4 ounces

Sulphite of Soda.............

80 grains

When this is fully dissolved add :

Powdered Alum.................

1/8 Ounce

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

1/8 Ounce

In place of the Citric Acid you may use 3/4 ounce Acetic Acid, but you must be sure that it contains 25 per cent. pure acid.

205. This bath can be used repeatedly so long as it retains its strength and remains sufficiently clear not to stain the film. The regular acid hypo fixing bath can be purchased in powdered form, ready for use, from any photographic stock house. There should be sufficient fixing solution in your tray to completely cover the films when immersed during the entire process of fixing, as otherwise the films will fix unevenly and stains will be produced if they are left partly exposed to the air. Non-curling films can be fixed in the plain hypo bath recommended for plates but when using this bath the films must be rinsed in three changes of clear water after fixing, and then placed into an alum bath prepared as follows:

Water.....................

16 ounces

Alum (crystals)..........................

1 ounce

Of this solution decant into a tray enough of the clear liquid to cover the films, and allow them to remain in this bath for five minutes; then wash in the ordinary manner. The alum hypo bath can be used continually until it becomes discolored or so exhausted that it will not harden the film.

HOME, SWEET HOME Study No. 4   See Page 370 By Grace E. Mounts

HOME, SWEET HOME Study No. 4 - See Page 370 By Grace E. Mounts.