Sources - Film Processing
III. The negative development
This chapter focuses primarily on black and white negative film development, as the development of color negative films is largely standardized by established processes (e.g. C41). Optimization of the development results or creative intervention is only possible to a very limited extent when processing color negative films.
Negatives should be able to be enlarged with as little effort as possible. This means that they should deliver images (positives) with good highlights and shadows and high sharpness in important details. The parameters chosen when developing the exposed film play a major role in the quality of the negative. In addition to the choice of developer type, these include temperature, agitation and time.
Types of developers
Different types of developers are available for processing black and white negative films. By choosing the developer, various properties of the negative can be optimized. Due to the chemical and physical conditions during development, these cannot be achieved together:
As fine a grain as possible
As sharp as possible
Maximum sensitivity utilization possible
The different photochemical developer substances available each have a characteristic profile of properties. Here are some of the most common types named with their properties. Different basic chemicals are often mixed in finished developer solutions in order to achieve a specific property profile. This list is not complete. In addition to these commercial substances, recipes with ascorbic acid (vitamin C) or coffee (caffenol) are also described. Although these are more environmentally friendly, they often lead to inconsistent results. Therefore, commercial products should have priority. These can also be handled safely if used and disposed of correctly. Ascorbic acid can also be found, for example, in Kodak's XTOL developer.
Overview of some developer substances (not complete!):
1.Hydroquinone developer: Hydroquinone is a normal to high-contrast developer substance that delivers good sharpness but relatively poor sensitivity utilization.
2. Metol developer: Metol works smoothly with good sensitivity utilization and high edge sharpness. It is usually used in combination with other developing substances (e.g. hydroquinone).
3. Phenidon developer: Phenidon is an extremely soft-working substance with good sensitivity utilization and moderate contour sharpness. Phenidon can replace Metol in all developer combinations (e.g. in special developers).
4. P-aminophenol: Developer substance that can be tuned in terms of contrast behavior and has very high edge sharpness.
5. N-Hydroxyethyl-o-aminophenol: delivers the highest sensitivity utilization while being a fine grain developing substance.
The substances are commercially available as formulated systems. These can be divided into universal developers, fine-grain developers, high-definition developers and sensitivity-enhancing developers. Some such systems are listed here as examples. A complete list cannot be presented due to the numerous developer chemicals available.
Universal developers are suitable for a wide range of applications without specific characteristics. In order to achieve a particularly low graininess of the negatives, one generally uses: Fine-grain developers, which usually do not fully utilize the film sensitivity and often lead to lower contour sharpness.
High definition developers (or high accuracy developers) deliver particularly high sharpness with relatively high graininess.
Developers who increase sensitivity make very good use of the nominal sensitivity, but usually at the expense of fine grain. The sensitivity increase is always compared to the results with the developer with which the nominal sensitivity was determined.
Due to the complex chemical processes involved in development, not every developer works equally well with every film. Therefore, the preferred film should be tried out in several developers.
For this purpose, the same subject is always photographed at different ISO values. The films exposed in this way are processed in various developers and the negatives are evaluated. Pay attention to sensitivity utilization, structures, resolution, graininess, contrast range, etc. In this way you get the developer/film combination that comes very close to the desired goal (image style) in a systematic way.
The final choice of this combination ultimately depends on personal preferences regarding the desired results. Further optimization is possible through experiments with different dilutions and other parameters. It has proven useful to first optimize a preferred system before trying out other developer/film combinations.
Parameters in film development
In contrast to those for color negative development (C41), the processes for developing black and white negative films are not standardized. This results in additional parameters with which the result can be influenced. If you master these, they represent further creative potential for image design.
The main parameters for black and white negative development include the choice of developer, its concentration, the temperature during development, its duration and the agitation during the process.
Development temperature
The higher the temperature, the faster chemical processes take place. Most black and white negative developments are carried out at 20°C, more rarely at 24°C. Various APPS offer conversion tables that can be used to determine the development time for different temperatures.
Developer concentration
Basically, a more concentrated developer solution works faster than a highly diluted one. This can be explained by the necessary diffusion processes that occur during the process. In a diluted solution it takes longer for new, unused developer to reach the latent film grain.
You can take advantage of this effect. If more diluted solutions are used, development takes longer. At the same time, the more exposed areas are not developed as quickly as in a concentrated developer solution. As a result, a higher dilution has a balancing effect, i.e. contrast-reducing.
If the film was exposed to a lot of hard, high-contrast light, the contrasts can be reduced during development by using higher dilution and extending the development time.
But there is also a chemical limit for this approach. If there is too little developer substance in the can, the film cannot be fully developed. The reaction stops because there is no more unused developer left.Care should therefore always be taken not to go below the manufacturer's instructions.
agitation
The micro-contrast and graininess are significantly influenced by the choice of developer and by the movement during development. These effects are also based on diffusion processes.
Strong agitation causes more exposed areas and coarser silver salt crystals to become overdeveloped.
These are constantly washed with fresh developer. Due to autocatalytic effects, a lot of elemental silver is quickly deposited here - a high-contrast, coarse-grained image is created.
In contrast, low agitation results in flatter, lower-contrast images with less graininess. Of course, this comes at the price of longer development times.
In any case, the agitation should take place calmly. the developer bottle should never be shaken. This leads to foaming and very unpleasant artifacts on the negative that damage it. After each agitation cycle, the can should be tapped on the table once to release any accumulated air bubbles from the film surface.
Duration of film development
The duration of a development has a major influence on the result. Negatives that have been developed for too long are very high in contrast and even have completely eroded highlights. On the other hand, too short a development results in thin, poorly drawn negatives. By the way, you can easily see whether the development times are correct if you look at the manufacturer's labels on the edge of the negatives. If this is only faintly visible, the development time was probably too short.
A special, experimental method for developing black and white negatives is stand development, in which the film stands in a heavily diluted developer for a longer period of time. Here too, it is important to ensure that there is always enough developer in the can; if necessary, you may have to use larger doses.
A common developer for the stand development of black and white negatives is, for example, Rodinal. When developing the stand, the developer is used highly diluted, for example in a ratio of 1:100. After pouring the developer into the developing can at 20°C, it is tilted 30 times / 1 min and then the can is pushed onto a flat surface (removes bubbles from the film surface). The film is then left to stand for a longer period of time (typically between 30 minutes and 1 hour).
After half of the stand development time, the stand is tilted 15 times / 30 seconds. Then the usual stop bath, fixing, rinsing and soaking in wetting agent for 30 seconds before the film is hung up to dry.
This method delivers fairly evenly developed images, especially when the exposure is spread. However, it is an experimental method and depends on various factors such as film type, developer dilution and development time. It may take a few tries to achieve the desired effect for the chosen film/developer combination.
Process of film development
Black and white negative film development typically takes place in four steps:
Develop, stop, fix, water.
APPS such as Massive Development offer great support here. These contain databases of tried and tested film/developer combinations with different dilutions and the possibility of calculating development times at different temperatures.
Finally, these programs “guide” you through the development process using a timer function. They are therefore a great help in systematic and standardized implementation. When you consider the multitude of possible parameters, this represents a huge simplification.
Four solutions typically need to be adopted for development:
Developer solution - the working solution is usually freshly prepared and only used once. The finished solution must then be brought to the exact development temperature. A typical temperature would be, for example, 20°C with a tolerance window of +/- 0.5°C.
Stop bath - 2% citric acid, alternatively 2% acetic acid, is suitable as an odorless stop bath. No special photo chemicals need to be used here; products from the drugstore are just as suitable, as long as they are pure acids. Perfume and soaps have no place in the development can. The stop bath should also only be used once to avoid contamination of the fixer.
Fixer - the fixing solution can be used multiple times - with a typical one liter batch up to 20 films can be fixed. As with the stop bath, the temperature should be 20°C +/- 5°C.
Wetting agent bath - this is the only solution for which distilled water should be used. All other solutions can be prepared with tap water.
It is advisable to have all solutions prepared at the right temperature before starting development, as the timing is of great importance for the result. An inventory list of the necessary equipment for film development can be found in the appendix. Steps in film development:
Wrap the exposed film onto the developing spool in complete darkness or a changing bag. Once the film has been completely rewound into the cartridge, it can be cracked in the changing bag using a bottle opener, for example, and the film can be removed. Alternatively, the end of the film can be pulled out of the cartridge using a film retriever. The beginning of the film must be trimmed so that it does not have any sharp or frayed corners. This means he can slide further along the spiral without any problem. The latter may only be used completely dry to ensure clean gliding when winding. The film must be wound neatly onto the spool to avoid development errors. When inserting the spiral into the developing can, do not forget the axis (steps 11 and 12), as this ensures light tightness. After the can is tightly closed, the further steps are carried out in daylight.
Pour the developer solution into the can. Make sure there is enough solution in the can to completely cover the film and start the timer. The time variance for filling and pouring should be a maximum of 1-2% of the total time. Development times between 5 and 15 minutes are therefore ideal.
Initial agitation (30-60s), then tap the can once on the table - this removes air bubbles on the film. Regularly agitate the can for 5-10s once per minute until the development time is up. Movements that are too fast can create foam and therefore defects on the negatives.
Quick and complete pouring of the developer
Put stop bath in the can and permanent agitation for one minute. Then pour out the stop bath.
Pour in fixer and agitate for 5 minutes at 30 seconds per minute (don't forget to tap on the table). Then pour out the fixer. Fixer solutions can be reused approximately 15-20 times. If you get slightly cloudy, milky negatives, fresh fixer is used. Milky negatives can generally can be easily re-fixed for 1-3 minutes. After fixing, rinse the can with film several times with water and then open it. The film is no longer sensitive to light.
Soak in lukewarm water for at least 10 minutes. (Ilford method or e.g. in a bucket or the filled sink).
Place the watered film in the wetting agent solution (in distilled water) for 30s. Wetting agents are surface-active surfactants that must not get into the development can. They can cause foaming and thus development defects. This final wet step prevents limescale edges and water stains.
Hang the film to dry overnight. It is now important to have a dust-free environment, otherwise dust particles will accumulate on the film.
Unlike the process diagrams above, the film should never be touched with bare fingers during the entire process or during further processing. Dust-free (talcum-free) disposable gloves have proven to be a good solution.
Assessment and archiving of negatives
Now the negatives have been developed and the film has dried. A pragmatic approach to further action will be described below. This is not the only path to the image. But use the current possibilities of the digital world in an efficient way.
The contact sheet
Negatives can best be assessed using contact sheets. A contact print is an unenlarged positive of a negative. It enables an initial assessment of the negative in terms of composition, exposure and contrast or tonal range. Since the entire film is shown on a contact sheet, you get a good overview and can select the best shots for enlargement.
In the analog laboratory, a contact sheet is created by placing the negative strips next to each other directly on light-sensitive photo paper, either directly in their transparent polypropylene cover or without a cover, and exposing them. The paper is then developed and fixed. A contact print is created without the use of magnifying lenses. To keep the negatives flat, they should be weighted down with a glass plate. The exposure time is chosen so that the edges of the film or the perforation are no longer visible on the print.
Contact sheets can also be created digitally using a scanner. For this purpose, the negatives are scanned on the computer. Suitable mid-range devices with a resolution of 2000 dpi are more than sufficient for this purpose. There is no need to use a professional scanner for this.After a little familiarization with the software (e.g. Vuescan), you can produce scans that can be used to easily assess the quality of the negatives.
Image editing and optimization are not carried out in the scanning program but - if desired - in a second step with the help of digital image editing programs such as Adobe Lightroom or Apple Photos. The parameters of the scanning process are chosen so that as much raw data as possible arrives in the resulting TIFF file. For a black and white scan this is 16 bit gray values, for color negatives it is 48 bit. With an additional IR scan, the scanning program can detect dust and remove it digitally.
Digitizing the negatives provides an overview of the results in a short time and without using photo paper or chemicals. Composition, exposure, tonal values, sharpness, etc. can be easily assessed on the computer. For enlargement in the darkroom, only the “successful” images are taken into account. This avoids disappointment and frustration in the darkroom.
As a “by-product” of this “hybrid” digital approach, there are digitized images that, with a little post-processing, can be used in parallel to work in the darkroom, for example for social media publications. In this way, the work in the darkroom can be divided into time blocks and thus be made much more resource-efficient and efficient.
Archiving negatives
The systematic storage and archiving of negatives makes it possible to find them again at any time, even after years. Additional information about the camera, lens, shooting conditions and processing parameters is useful because it helps, for example, to optimize future images.
Negative sleeves are made from different materials. In addition to the archival, breathable glassine sleeves, transparent polypropylene sleeves are also available. The latter offer the advantage that the negatives do not have to be removed from the cases for the contact print.
The negative sleeves should be stored in dust-proof folders. These consist of an “inner” folder, which is then put into a box. These folders should be stored in a normal indoor climate, protected from direct sunlight. Moisture can lead to mold growth.
The negative sleeves then have to be labeled. For this purpose, it has proven useful to use a fixed numerical code that contains, for example, the year (Y), the month (M) and a sequential number (X), e.g.: YYMMXXXX.
These numbers can be stored in a spreadsheet with the essential information about the film. You can then easily research this database on your computer and then find the negative you are looking for in the similarly labeled folder.
IV. The magnification
After identifying a negative for enlargement from the contact sheet, work begins in the darkroom. As in a good kitchen, good preparation is a big part of success. The following chapter will show you how to set up and test a darkroom. An inventory list can also be found in the appendix. It will then be described what the enlargement process looks like to create the finished image.
This is a list of useful sources dealing with film processing:
Analoge Fotografie - Filme Entwickeln
Steffen Schüngel - Negativ- und Entwicklungsfehler beurteilen und vermeiden
Fotoimpex - Fotochemie bestellen
Kwerfeldein - Crashkurs Filmentwicklung
Kwerfeldein - Crashkurs Filme Scannen
Fotografie in Schwarz-Weiß - Der Negativ-Entwicklungsprozess