When we announced in the October issue of Studio Light that the new Eastman School of Professional Photography would be presented in motion pictures we felt sure that the innovation would be welcomed.

We knew the new school would do just what we claimed for it - present the various subjects more graphically and give a greater amount of useful information and instruction in a shorter space of time.

And we hoped that by saving this time there would be more chance for open forums - that the school sessions would develop into a series of instructive pictures, talks and discussions that would approximate a small get-together convention.

The first three schools have done all of these things and more. The attendance has been far greater than at any previous schools in the same localities. The motion picture idea has been a success and all who have seen it like the picture much better than the old style of demonstrations. The ideas are more clearly and quickly expressed by the actors than would be possible by inexperienced models and everyone sees the demonstrations and can read the titles without depending upon their ears.

The Eastman School On Its Pre Holiday Trip StudioLightMagazine1923 275

PORTRAIT FILM NEGATIVE, VITAVA PRINT

By D. D. Spellman Detroit, Mich.

The demonstrators or lecturers have a much better opportunity to discuss the various subjects treated and there has been no difficulty in getting those in the audiences to ask questions. These questions bring out very interesting discussions of the difficulties a man encounters in his every day work and the solution of these problems fully pays him for the time away from his studio.

A photographer at the Buffalo school remarked that he would not take $100.00 for what he had learned in two days, and from the general remarks of satisfaction we are sure there were many others who felt the same way.

We are not yet in a position to announce the itinerary of the school for the coming spring and summer but we will keep you informed through this magazine and we will send you reminders far enough in advance to permit you to plan for your school.

The Prevention And Remedy Of Imperfections In Prints

By imperfections in prints we mean any form of deterioration due to the improper use of chemicals or faulty manipulation which causes chemical changes that are injurious to the print.

One very common print defect is the formation of a white powdery sediment or scum which covers the print and does not wash off. If such a precipitation on prints is encountered, and can be removed by washing the prints in a 5% solution of sodium carbonate, you can be quite sure it is caused by aluminum sulphite in your fixing bath.

The acid fixing bath consists of a mixture of hypo, sodium sulphite, acetic acid and alum. As the sodium sulphite and alum form aluminum sulphite the fixing bath is really made up of hypo and aluminum sulphite dissolved in acetic acid.

Aluminum sulphite in solution has an important function in the fixing bath and it is kept in solution by the acetic acid. But this is what happens when a fixing bath is overworked or contains acetic acid which is not a 28% pure acid.

The Prevention And Remedy Of Imperfections In Prin StudioLightMagazine1923 277

PORTRAIT FILM NEGATIVE, VITAVA PRINT

By D. D. Spellman Detroit, Mich.

The developer carried into the fixing bath with the prints contains sodium carbonate and this neutralizes the acetic acid. When the acetic acid is so used up or neutralized that it falls below a certain point it is no longer able to hold the aluminum sulphite in solution. As a result it precipitates on the prints and not being soluble in water it remains in the pores of the gelatine unless it is dissolved and washed away.

The way to prevent this precipitation is to use pure 28% acetic acid and never use a gallon of acid fixing bath for more than four gross of 4 x 6 prints or their equivalent. Another way is to use the acid stop bath between developing and fixing. This bath greatly reduces the sodium carbonate in the developed print so that very little of it is carried into the fixing bath.

To remove aluminum sulphite deposit from prints make up a 5% solution of sodium carbonate and do not have it over 65° F. Place the prints in this solution for several minutes and then wash thoroughly.

The second form of imperfection we will treat on develops with age and is most likely to be encountered when prints on developing out paper are brought to you to be copied. The print seems to have faded and in the highlights where there is the least silver the image is a yellowish white.

The silver image has been converted to a modification of silver sulphide. The print was fixed in a sulphurized fixing bath that was slowly depositing sulphur, some of this sulphur remained in the print, even after washing, and the silver image has gradually turned to silver sulphide.

This trouble will not occur if prints are thoroughly fixed in a fresh, clear, acid fixing bath, that is not depositing sulphur, and then thoroughly washed.

To restore the print it is advisable to clean it thoroughly. This may be done with a piece of art gum. Grease marks can be removed with gasoline and the print finally rubbed over with alcohol. If the print is mounted soak it in water and remove the mount.

Fix the print thoroughly in fresh hypo to remove any silver that has not been oxidized by the original development. Wash thoroughly and harden the print for two or three minutes in a 3% solution of formalin and wash again.

If the highlights are stained with silver this can be bleached out but the operation is dangerous for two reasons. It requires a deadly poison (2% solution Cyanide of Potassium) and not only is this deadly poison but there is very great danger of bleaching out the silver image as well as the stain.

If the highlights are not stained the entire image may be bleached to silver chloride in the following bath:

Solution A

Potassium Permanganate 75 grains Water 32 ounces

The Prevention And Remedy Of Imperfections In Prin StudioLightMagazine1923 279

PORTRAIT FILM NEGATIVE, VITAVA PRINT

By D. D. Spellman Detroit, Mick.

Solution B

Sodium Chloride (table salt) 2 1/2 ounces Sulphuric Acid (C P) 1/2 ounce

Water to make 32 ounces

Use equal parts of A and B. Bleaching will require three or four minutes. These solutions keep well separately but not when mixed. Be sure that the permanganate is thoroughly dissolved as small particles will cause spots.

This bleaching solution causes a slight stain which is removed in a 1% solution of sodium bisulphite. The print should then be rinsed well and exposed to a strong light (daylight if possible) while it is developed in an Elon-Hydro-chinon developer. The exposure to light is required to form a strong image and as there is nothing but the original image to develop the more light the better. Wash the print thoroughly.

The common stain caused by oxidation of the developer is also removed by bleaching and redeveloping as we have just explained. Prints are sometimes exposed to the air during rinsing or if they are not thoroughly immersed in the fixing bath and the result is a yellow oxidation stain. As a rule such prints are made over. But if, for any reason, it is desirable to remove the stain the permanganate bleach dissolves it away, re-developing brings back the image, bisulphate clears it and a perfect print is the result.