Uranium Intensifier

No. 1. Nitrate of Uranium............15 grs.

Distilled Water................ 4 oz.

No. 2.

Ferri-Cyanide of Potassium... 15 grs. Distilled Water................ 4 oz.

For use mix 3 oz. of No. I, 3 oz. of No. 2 and 1 oz. of Glacial Acetic Acid. The solution is poured over the late, which has previously been washed, and the tray is kept rocking constantly. At first the plate assumes a ark brown color and later a red color, which prints very well. Do not leave the negative in the intensifier too long as the color is somewhat deceptive and a negative while in the tray may not look strong but when held to the light may be found to be fully intensified. The plate should then be washed for about a quarter of an hour. If washed too long the intensification will be removed and yet it must be washed sufficiently to remove 1 chemicals from the film. At first the water runs off the plate as though the latter were greased. Washing must be continued until the acid, which causes this greasy appearance, is entirely removed. This solution may also be used for local intensification, i. e., intensification in spots or parts. To do this you first intensify the entire negative aud then proceed to reduce the intensification in places by the application of diluted ammonia with a camel's hair brush. One part of ammonia, specific gravity .96, in twenty parts of water is about right. The intensification fades away under the application of the ammonia. When applying the ammonia a tray of water should be at hand and if the intensification is fading too much or beyond the spots you desire to bleach, dash water ever the plate, or better still, hold it under running water. Keep the plate flat when applying the ammonia and apply a little at a time, watching carefully to see that it does not run where it is not wanted. If it is a sky that requires reducing, stand the plate on edge and the sky downward so the ammonia will run away from instead of towards the picture. After this treatment the negative should be washed for fully one hour in order to remove the last traces of ammonia.

Very often the amateur in seeking to bring out every detail in his plate over developes it, i. e., deposits silver on it with such a lavish hand that when he comes to print from the negative he finds it so dense as to require hours to print it. This may be remedied by what is technically known as reduction. There are several formulas for reducers and there is little choice between them.

Hammer's Reducer

No. 1. Water...........................16 oz.

Ferricyanide of Pottassium ......1 oz.

No. a.

Water...........................16 oz.

Hyposulphite of Sodium....... 1 oz.

Keep solution No. 1 in a brown or dark-blue bottle and in the dark room, as it is effected by the light. Take a sufficient quantity of No. 2 to cover the plate in a tray, and add to it a small quantity of No. 1; immerse the plate and watch it carefully. If the solution contains enough of No. 1, the reduction will proceed rapidly. If certain parts only of the negative are too dense, apply the reducing solution to those parts, while wet, with a pencil brush. Wash the plate thoroughly after this treatment.

Lainer's Reducer.

Potassium Iodide............. 10 grs.

Sodium Hyposulphite......... 1/2 oz.

Distilled Water................2 1/2 oz.

If the negative has been dried it must first be thoroughly soaked as when intensifying, but if still wet the reducer may at once be applied by flowing over it in a tray but the plate should not be allowed to reduce too far but rather removed before it has reached the apparently right reduction and washed in water. If not reduced sufficiently it can again be inserted.

Belitzki's Reducer

Potassium Ferri Oxalate...................................................... 1/2 oz.

Sodium Sulphite..............................................................180 grs.

Water......................................................................... 10 oz.

When this has dissolved add:

Oxalic Acid, Crystals........................................................ 30 grs.

Now measure out

Sodium Hyposulphite........................................................2(1/2) oz.

Water ........................................................................ 5 oz.

And when dissolved add this to the above. Before the oxalic acid is added to the first solution it will be an ox-blood red but after the addition will turn green. It should then be poured off carefully and added to the hypo solution. This solution is applied either to a wet plate or one which has been soaked, by flowing over it. Plates that need local reduction only may be treated with any of the above reducers by applying it with a camel's hair brush the same as directed for intensification.

Reduction by means of alcohol is very efficient and convenient under some conditions as it requires no chemicals aside from the alcohol. It is mostly confined, however, to negatives that require local reduction only. The negative should be laid, film up, upon a flat surface like a table or a piece of plate glass and the portions to be reduced are rubbed vigorously with a piece of chamois leather wet with alcohol. The finger of an old kid glove when turned inside out will do very well, but care must be exercised not to let the seam in the glove come in contact with the film. It should be turned inside out because the alcohol might make the dye in the glove "run" and stain the negative. Do not be afraid of hurting the film, provided the negative is thoroughly dry, for instead of softening the alcohol hardens the film, and after it has been rubbed for a while the film will shine like a piece of polished steel, and all the dull, downy appearance that is often seen on over developed negatives will be entirely removed. Keep the leather wet with the alcohol or you will effect little. On examining the leather you will see that you have removed some of the silver from the film as the leather has been blackened thereby. One of the advantages of this process of reduction is that you can stop at any time and take a proof and if not satisfactory you can proceed with the reduction. We should imagine that a negative rubbed with alcohol would wear much better than one which has not and be less liable to be scratched and finger marked, for the surface of the film appears to be as hard as sole leather. This is an excellent process for treating halation. Aside from being too dense or too thin negatives often have other faults prominent among which are the following: