Possibly it is a little early to speak of the problems that confront you in warm weather, but it is never too early to speak of anything that has to do with the fixing bath. And the "short stop" or "rinse bath" does have considerable to do with the fixing bath.

A great many photographers do not consider a rinse bath between developing and fixing essential, but if the life of the fixing bath is to be normal - if it is to fix properly as long as the chemicals it contains would lead one to believe it should fix. then the rinse bath is essential.

A properly prepared rinse bath has three distinct functions. The first is to stop development. And development, as you know, is due largely to the acceleration produced by the alkali, which is the carbonate of soda.

The rinse bath being acid naturally stops development because the acid neutralizes the alkaline developer that remains in the negative film. Without an acid rinse bath the negative would continue to develop until it reached the fixing bath, even though it were rinsed in water.

We might say that the second function of the rinse bath is identical with the first so far as the action of the bath is concerned. The same action that stops development, conditions the negative for the fixing bath.

If an acid rinse bath is not used the alkaline developer is carried into the fixing bath, where it is neutralized by the acid in this bath. There is no immediate bad result if the fixing bath is a fresh one, but the efficiency of the bath is needlessly reduced.

The sulphite of soda in the fixing bath has a preserving action in the presence of acid, but when the acid becomes exhausted the sulphite fails to act, with the result that the developer carried into the bath oxidizes, turning it brown and staining the negatives. As a result it must be discarded sooner than would otherwise be necessary.

The Three Advantages Of A Rinse Bath StudioLightMagazine1923 122

FROM A PORTRAIT FILM NEGATIVE

"Sheila" London Salon, 1922

By Monte Luke

Sydney, New South Wales

The third function of the rinse hath is to pre-harden the gelatine film of the negative. Some may think this unnecessary, but we have found that both plate and film negatives that have been allowed to remain for two or three minutes in the rinse bath will stand much higher washing temperatures without blistering, softening, frilling or reticulating.

Everyone who works carefully rinses a negative between developing and fixing. Why not, then, use a rinse bath that has the beneficial effects we have mentioned?

The formula has been greatly simplified by discarding Sulphuric Acid in favor of 28% Acetic and reducing the alum considerably. As we now recommend it, to one gallon of water add two ounces of Potassium Chrome Alum and three ounces of Acetic Acid, 28% pure.

This is simple to prepare and, if for no other reason, is worth while because it prevents contamination of the fixing bath with the oxidation products of the developer. And when you have acquired the rinse bath habit you are not likely to be encountered with hot weather troubles.

Velox Enlarging Printer For The Commercial Finisher

The Enlarging Printer is a device that will not only make more business for the finisher, but more profitable business as well. It is a printer, but the prints it makes are enlargements on Velox paper, 3A size from 1 5/8 x 2 1/2 inch negatives and 5 x 7 or 3A size from 2 1/4 x 3 1/4 inch negatives. And they are made at practically the same speed and cost as contact prints of the same size because the Printer uses a powerful concentrated light and is fixed focus, which greatly simplifies its operation.

As we see it, the finisher, instead of asking his customer how many 1 5/8 x 2 1/2 or 2 1/4 x 3 1/4 prints he wishes made from his negatives, can soon accustom the owners of these small cameras to have all 1 5/8 x 2 1/2 inch negatives printed in the 3A size and all 2 1/4 x 3 1/4 negatives in the 5 x 7 or 3A size if he has a Velox Enlarging Printer in his printing room.

With such an efficient printer the price of these larger prints from small negatives can be made attractive and still allow the finisher a better profit than he would make on contact 3A or 5 x 7 prints and a very much larger profit than he could make on the small contact prints.

Velox Enlarging Printer For The Commercial Finishe StudioLightMagazine1923 124

FROM A PORTRAIT FILM NEGATIVE

By Monte Luke

Sydney, New South Wales

Velox Enlarging Printer For The Commercial Finishe StudioLightMagazine1923 126

Velox Enlarging Printer

While the process is really an enlarging process, the printer operates very much as a contact printer with the one exception - the negatives are not in contact with the paper.

The powerful printing light is furnished by a -250 watt, monoplane filament, Mazda lamp and this light is projected by a special reflector through three condensing lenses and an f .6.3 Kodak Projection Anastigmat Lens to the Velox paper.

The average printing exposure is from 2 to 4 seconds, though this time will vary, depending entirely upon the density of the negatives. There are two negative holders that slide into the cone of the Printer, one for each size of negatives accommodated, and there are three paper holders, one for each size of enlargement.

The negative holders can be used either for single negatives or for the uncut strip of film. The paper holders may be quickly changed and as the paper is placed in the holder against the guides and the holder closed, the light is automatically switched on and the exposure made. Obviously the printer can be used in any light that is safe for printing Velox.

With the lens in normal position the enlargement from the 1 5/8 x 2 1/2 inch negative is 3 1/8x5 3/8 on 3 1/22x5 3/4 Velox paper, giving a 3/16 inch white margin.