This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Tank Development. Or stand development, is constantly growing in popularity, due to its simplicity and the even quality of its results. There are several precautions which must be observed with the tank method to be used successfully. The tank should be used for no other purpose. The grooves may be wide enough so that two plates (placed back to back), can be put in each groove, and the plates should not come within one-half inch of the bottom of the tank.
592. When any alkaline developer is used the temperature should be fifty-five degrees Fahrenheit, and never allowed to rise higher than sixty degrees Fahrenheit during the time of development. Always test temperature with a thermometer, as a temperature above sixty degrees is liable to cause uneven development, stain and fog.
593. When using Cramer's (Liquid), Acetone, temperatures up to seventy degrees can be used with perfect safety, as this form of developer is not alkaline. The developer should be thoroughly mixed before putting the plates in the solution. Move each plate up and down quickly several times to break air-bells, and after the plates have been in the tank about five or ten minutes, reverse their position, putting the top of the plate where the bottom was to insure even development, and to avoid streaks. When putting plates into the tank be sure that your hands are free from other chemicals.
594. Negatives made of subjects against white grounds may need finishing by tray development in a strong concentrated developer containing a heavy dose of a ten per cent, solution of bromide of potassium.
595. There is a point beyond which the developer cannot safely be diluted without causing peculiar streaks and blotches (see note A at end of Developers), stain and fog, due to the solution decomposing before development is complete.
After development, the tank should be thoroughly cleaned to prevent stain.
Tank Developers. Any of the Cramer standard alkaline developers can be used for tank developers, by adding to the tray developer made up according to formula given in this article, two to three times its bulk of water, so that it takes about one-half-hour to develop at a temperature of fifty-five degrees Fahr. Cramer's pyro - acetone developer, as given in this article, can be used by taking one ounce of A, two ounces of B, and thirty ounces of water.
597. Pyro - Metol - Acetone Developer for Tray or Tank Developer.
Cramer's Dry Sulphite Soda
. 4 ounces
Cramer's ( Liquid) Acetone.
r use in tank take:
For use in tray take:
15 ounces A
1 ounce A
15 ounces B
1 ounce B
200 ounces water
5 ounces water
We do not give the time required to develop plates with any of these formulae, as some users might consider that the time given was a fixed factor, when it depends entirely upon each user's idea of what is the proper intensity. When the time is once settled, however, it can be depended on to give the same intensity with the same temperature and strength of developer, provided the exposures are the same.
598. Peculiar streaks and blotches in the shape of brush marks, finger marks and insensitive spots, appearing as though the plate had been scrubbed with a dirty or greasy brush, or improperly cleaned, are caused by the uneven action of the developer, if it is too old or too much diluted. This trouble is more liable to occur if hydroquinone is used in connection with eikonogen or metol; and can be prevented by using the developer more concentrated or by a radical change to a different developer.
599 It is hard for a user of dry plates to believe that this trouble is not the fault of the plate, as its appearance and disappearance is erratic, but the most skeptical can convince themselves by making up a fresh and stronger developer from chemicals of known purity, and which have not deteriorated by long standing. Then develop more of the same lot of plates, none of which will show any markings.