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Colored acidification equipment in our homes

In the beginning, we considered developing color prints at home too difficult for everyone but the most experienced hobbyist. Nowadays, modern equipment, and with it fewer chemical processes,
Temperamental (Temperamental) made color development almost as easy as black and white development. Indeed, we can even say that making color prints can in some ways be easier than making black and white prints, provided we choose the most appropriate equipment.

While it is possible to develop black-and-white prints in simple open vats, more retouching equipment is generally required to practice color printing, for a number of reasons.

And since there is no good safety light for colored paper to begin with, the development has to take place in almost complete darkness - this means that transferring the print from one basin to another will be an annoying issue and causes pollution - and the second thing is that color printing needs accuracy in temperature control, which is difficult Achieved with open tubs. The third thing is that the chemical compounds involved in the development of the color print will quickly oxidize in open vats, thus emitting irritating fumes in the narrow, confined atmosphere of the dark room, in addition to the difficulty in preserving these chemical compounds at the exact concentration required.
As for the simplest and most common solution to these dilemmas, it is the use of a special development period for the print, despite the existence of some new endorsement methods, which are still much more expensive today.

Developing drums:
As is the case with the film endorsement basins, we find the color print development drums, which are light-proof cylinders usually made of plastic, with a special hole at one end that allows the pouring and ejection of chemical compounds without light reaching the print. Once the print is wrapped and installed around inside the drum and then close the lid.
The whole process can be carried out under the normal light of the room with the use of enough chemical compounds to cover the print only, and until the moment of using the solutions, it can be kept covered inside containers placed in a water bath, which reduces the certainty to the bottom and facilitates the issue of precise temperature control a lot.
There are two main types of drums, a type that is filled with chemical compounds and is in a horizontal position. It is a type of drum that usually rests on short legs, while the chemical compounds are poured into it. As for the print inside the drum, it is installed around the inner wall so that the chemical compounds form a small pool between the two ends of the paper slide, while the drum is stable on its legs. Acidification begins here when the drum is rotated over the working bank, which allows the chemical compounds to flow onto the print page.

The second type is fed vertically and has a cup under the cover of the drum that accommodates the chemical compounds. When this drum is turned to a horizontal position, we allow the chemical compounds to flow out of the cup and rest on the print.
We point out here that the horizontal and vertical feeding drums use relatively small quantities of chemical compounds that are disposed of after the development of each print. This confirms that the concentrations of the solutions do not change. As for moving the prints and keeping them immersed in the acidifying solutions, this is done either by manually rolling the drum back and forth on the work bank, or by using a motor-powered drum roller. It's a constant move that usually gives very similar results.
However, vertical drums are a little easier to use because they can be filled with water to pre-heat the drum. While water may leak from the narrow openings in the horizontal drums while filling them.
There are drums with ribbed inner walls, and this is good because it prevents chemical compounds from getting trapped behind the drum, which may cause contamination of subsequent solutions in smooth-walled drums. The best drums are those that can be completely disassembled for cleaning after use.

Moreover, most of the drums can accommodate more than one print at the same time, and most of them are characterized by movable spacers fixed in a slot on the walls of the drum to prevent the prints from slipping on each other, and this is a great advantage as long as it means the possibility of developing two or more prints at one developing speed. It is usually better to buy a large drum to the extent that can be paid for, although the cost will be high when we reduce one print in a drum designed to accommodate enough chemical compounds for four prints.

Extra equipment:
Although using a developing drum is a simple process that requires only a few extra equipment, there are many accessories that make developing a print much easier, especially when we are in the process of

Make prints in large numbers.

One of the most useful additions here is the motorized drum roller.
After the disappearance of the first fun as a result of making self-colored prints, we may find that moving the acid drum manually is a very cumbersome matter - in which there are causes of boredom enough to endanger the stability of the acid - here comes the motorized drum rotors to remove this fatigue.
These rotors are available in many types, the simplest of which is the simple rotating base that rotates the drum on its horizontal axis, some of which rotate the drum in one direction only, while there are other models that have eccentric rotors that shake the drum slightly during its rotation, thus achieving better movement.
The most suitable are those rotors that include a reverse motor that works automatically to rotate the drum in one direction first, then in the other direction.

In order to avoid the issue of warming up the drum before developing each print, and to ensure accurate temperature control throughout the process, we can use special rotors for the drum that include a water bath that is thermostatically regulated - by means of an automatic device to adjust the temperature - here the drum is rotated in the machine while it is partially immersed in the water bath. There is usually a section of the bathroom in which bottles can be placed for storing chemical compounds to ensure that they are also on the correct acidification temperature. They are expensive devices, but they give wonderful results. There are also temperature control units concerned with chemical compounds only, known as tempering boxes. Most of these are based on the use of water baths, but there is a unit that heats chemical compounds with a hot air fan. Tempering boxes are not necessary, but some printers find them very useful.
One of the devices you can use to make the colored development much easier is a programmable timer and devices like that. The counters are usually “simple stimuli with discs into which small plastic indicators can be slid.” When each pointer reaches a reference point, a bell rings, reminding us to remove one of the solutions and move on to the next acidification step. There are also expensive electronic time counters, some of which can be connected with the rotating drum so that the acidification stops automatically at the correct time.

Other working methods:
Although drums are typical for hobbyists working on a small scale, they still have a number of disadvantages when it comes to burning a large number of prints or large individual prints. We have to clean and dry the drum completely after developing each set of prints. Also, the spacers that hold the prints apart in the drums may also cause a slight lack of similarity in the acidification at the edges of the prints, and these can be cut after the print has dried only. Causing damage to the sensitive layer in the wet print, which is a quickly damaged layer, if we are in a hurry in particular.

One of the simple solutions to the problem of the limited size of the drum is to use a larger length. Drums for small-scale operators typically start at a print size of 1068 inches and go up to approximately 16 x 20 inches. However, there are very large drums, measuring up to 24 x 32 inches. However, these are moving away from the simple drum principle, as they accommodate a large number of smaller scale prints, operate mechanically, have thermostatic control of solutions and temperatures, and even include an automatic means of emptying chemical compounds.

As for semi-professional printers, the simplest alternative is a deep tank acidifier. This is similar to a very ordinary tank in principle, but with the absence of some disadvantages. In this case, deep solution tanks are kept at a constant temperature with a thermostatic heater. Here, photoexposed strips of paper are taken. It is installed in hangers and placed in the basins.As for the oxidation, it decreases in the small surface area of ​​the chemical compounds exposed to the air.
We point out here that these units should be used in complete darkness, and since they are compact and easy to work with, this does not create a major problem and is particularly suitable for use with Cibachrome.. as long as the ordinary light of the room can be lit. on the results.

As for the chemical concentrations, they are maintained by feeding - adding a small amount of fresh solution to each basin after each acidification process - and the floating covers of the basin prevent the chemical compounds from oxidizing when the unit is not in use.
Rotary acidifiers are a more sophisticated method of print development, and are usually only found in professional darkrooms, although there are a few smaller rotary acidifiers suitable for home use. These consist of a motor-driven unit with temperature control and a means of automatic feeding of chemical compounds which are moved over the photoprinted paper in a series of rotors and in chemical baths. It is sufficient here to feed the prints exposed to the light into a slit at one of the two ways of the device, where an acid comes out completely from the other side after a few minutes. This means that a continuous flow of prints is produced with little effort after preparing the device. Each printing session. It should be noted that rotary acidifiers that make prints from negatives cannot usually be qualified to make prints from slides, and vice versa. The main disadvantage for the hobbyist is that the smaller rotary acidifier is very expensive.

Other approaches to developing a color print have been tried in the past, such as surface flow acidifiers, which are based on passing a thin layer of acid solution over the print page, and the color canoe, which was an intermediate stage between vats and drums.
As for the alternative method that competes with the supremacy of the drum in the small dark room, it is the Kodak Ektaflex Print Making System, which uses real-time image technology to make prints from slides or negatives with only one developer, although this device only works with Kodak products, which are relatively expensive, and for the current stage, the color developing drum is still the simplest and most economical way for photographers to make prints from colored negatives and slides⏹