The Film Developing Cookbook

Bill Troop, Steve Anchell

• Editore: Routledge
• Anno: 2019
• ISBN:
  9781315468433
• Edizione: 2
• Argomento: Kunst
• Categoria: Fotografie

The Film Developing Cookbook, 2nd edition is an up-to-date manual for photographic film development techniques. This book concentrates on films, their characteristics, and the developers each requires for maximum control of the resulting image.

For two decades The Film Developing Cookbook has helped photographers acquire a working knowledge of photographic chemistry—what photo chemicals do and why—for black and white film developing. Now reissued in a revised and fully updated edition, this must-have manual for photographic film development techniques covers films, their characteristics, and the developers each require for maximum control of the resulting image. Readers will learn how to mix and use photographic solutions from scratch, and even how to create new ones. Includes invaluable information about films, developer ingredients, formulas, speed increasing, mixing and storing stock solutions, stop baths, fixers, washing, and chemical safety.

A must-have for analog photography enthusiasts and any photography students using the darkroom. For in-depth discussion and questions on all things film or darkroom join the Darkroom Cookbook Forum, www.darkroomcookbook.com

Chapter 1
DEVELOPER CATEGORIES

Each combination of a particular developer and film yields a unique negative. Differences may be great or small, but there will be differences. And those differences are an important ingredient in the recipe that, as photographers, we use to create our unique signatures.

This chapter outlines the main developer types, and suggests how to match them to particular films, formats, and pictorial situations. There are four key qualities to consider: sharpness, graininess, contrast, and speed.

Definition in photography

Definition in photography is the subjective impression of how clear the detail in a photograph appears. Definition includes many interrelated factors: graininess, contrast, resolving power, and sharpness.

Sharpness is the most important of the four. Sharpness has an overwhelming effect on viewers. On a gut level, we can forgive a photograph nearly any technical fault, as long as it appears to be sharp. But what does sharpness actually mean? Subjectively, we all seem to know. But sharpness is as hard to define as it is to measure: distinctness of outline or contour, abruptly or strongly marked—these are some of the ways people have attempted to pin down the concept of photographic sharpness.

Acutance is an objective measure of sharpness. Developers which enhance sharpness are often called acutance, high acutance, or high definition developers. Different developers, as well as agitation techniques, can have an enormous effect on acutance levels and, consequently, how sharp negatives will appear.

Resolution or resolving power is measured by examining a target comprised of parallel black bars on a white background, set up in a lines per millimeter arrangement. The smallest set of bars that is discernible equals the resolving power of the film or lens at hand. Decades of experience have shown that resolution is a poor guide to perceived sharpness—see the illustration at the right.

Other ways to measure photographic quality include DQE (Detective Quantum Efficiency) and MTF (Modulation Transfer Function).

The top photo shows good resolution but poor sharpness. The bottom photo shows poor resolution but good sharpness. For Geoffrey Crawley’s definitions of sharpness and definition, see Chapter 5.

Graininess

Basic grain size is predetermined by the manufacturer. Slow films have finer (smaller) grains, fast films have coarser (larger) grains. Graininess is the subjective perception of grain. Granularity is a theoretically objective measurement which correlates with our subjective perception of graininess.

Graininess can be significantly altered by the developer and by the time film spends in the developer. Moreover, each developer creates its own unique grain pattern: tight; fuzzy; soft; hard-edged; or somewhere in between. The grain pattern can make or break an image. For a portrait or a commercial photo you will probably want a virtually invisible fine grain pattern. However, a photographic essay on junkies in a shooting gallery might have greater impact if the photos are sharp with an obvious grain pattern.

“We search for truth; sometimes we find beauty.”

—LISETTE MODEL

As a general rule, solvent developers emphasize fine grain at the expense of sharpness; non-solvent developers emphasize sharpness at the expense of fine grain.

Contrast and gradation

There are three kinds of contrast: macro, local and micro. The curve we measure with a densitometer and usually see in film tests and manufacturers’ literature is the macro characteristic curve—the contrast of large areas of the negative. These curves are generally measured by a device which covers a 2mm diameter area, a substantial portion of a small negative.

The micro characteristic curve is measured over a much smaller area. The micro characteristic curve of a film is always greater in contrast than the macro characteristic curve. A range of tones in a small area is reproduced with higher contrast than a similar range of tones in a large area. However, an area that was micro characteristic on a 35mm negative may be almost macro characteristic on an 8x10 negative of the same scene. Therefore, the larger the film, the truer will be the reproduction of micro-contrast.

Macro-contrast refers to the big effects that will tell us what grade of paper we will need to print a negative, or whether we can print a negative at all. A high contrast negative will need a low paper grade or filter; a low contrast negative will need a high paper grade or filter. In most cases, macro contrast depends not so much on the developer but how long the film is developed. The greater the development time, the greater the contrast.

When Zone System photographers expand or contract their negatives (N+1, N-1, etc.) they are manipulating macro contrast.

Local contrast is a synonym for gradation—a term we often use to discuss tonality and tonal differences.¹ It refers to macro contrast, but only over small parts of the characteristic curve. For example, when we refer to midtone gradation, we mean the separation between Zones III and VI.

A developer with “rich midtone gradation” increases separation in the midtone part of the curve (Zones III to VI). A developer with high toe contrast has a short toe (Zones I and II). The straight line starts almost at once, and midtones might be compressed. A “brilliant developer” has a steep shoulder: highlights (Zones VII and higher) are widely separated but could be hard to print. A compensating developer has a smooth, long shoulder. Highlights can be dull, but easy to print.

Macro gradation characteristics are built into the film, and can be determined by testing with a densitometer. However, different developer formulations, dilution techniques, and agitation methods, have a significant effect on local contrast/gradation.

Micro-contrast explains why we can experience difficulty printing fine highlight detail with tabular grain films. Even though they have fine grain and high sharpness, tabular grain films have too much micro-contrast in highlight areas. The reason is that the lateral dimensions of flat tabular grains (which face the light) are so much larger than conventional grains. Because they do not scatter light as well as conventional grains, when there is an abrupt change in exposure level, there is also a tendency to high contrast in micro areas. The visual result is high sharpness but poor gradation.

Micro-contrast effects are not as well known, but they are just as important as macro and local contrast when evaluating image quality. These areas, though not apparent to most viewers, play a great role in the emotional response to the image. They can be emphasized through the choice of developer and degree (overall time and frequency) of agitation.

The micro-contrast characteristic curve is steeper than the macro-contrast curve. How much and where depends on the film, the developer, and the size of the film. In practical terms, when you are using a film/developer combination with high micro-contrast, you will notice that small areas, like specular highlights, may be hard to print. Since micro-contrast relates to size it is automatically lower with larger film sizes. That is the main reason photographers interested in capturing the finest highlight detail use the largest sheet film they can.

While it is possible to make a good, sharp landscape photo with 35mm, the same scene with a 4x5-inch view camera will reproduce micro areas with infinitely smoother gradation. On the other hand, as long as there is no camera shake or excessive movement by the subject the high micro-contrast of smaller negatives can give the impression of biting clarity to a negative. But this impression is achieved at the expense of smooth gradation in small areas. With high micro-contrast, small light-grey areas may become almost white in the print, and small dark-grey areas may become almost black. That is what we mean when we talk about ‘losing smooth gradation in small areas’. But there is a benefit: we gain sharpness. (One way digital sharpness filters work is by increasing micro-contrast while attempting to leave macro-contrast unchanged.)

Speed

Developers can be divided into three speed categories:

• those which decrease the film’s rated speed
• those which maintain the film’s rated speed
• those which increase the film’s rated speed

In general, developers that decrease speed produce lower graininess, while those that increase speed produce higher graininess. In addition, developers that increase speed usually have less latitude for incorrect exposure than developers that maintain or decrease speed, while developers that decrease speed sometimes provide more latitude.

Negative quality

If there is any secret to obtaining high sharpness and fine grain, it is to ensure that the negative has a low density range. Maximum density should not exceed 0.9 above base+fog for small negatives, or about 1.2 for larger negatives. This means that 35mm negatives of normal scenic contrast should ideally be developed to print well on grade 3 paper.

Crawley 60/61 discusses developer interlocks in more detail than is usual in the literature. The reason may be that Crawley was one of the few chemists who had the opportunity to design such a wide range of developers over a long period of time.

Medium and large format negatives should be developed to a slightly higher contrast, to print on grade 2 paper. That said, our suggestions for specific grades are offered in a general spirit, since manufacturers of graded papers don’t use these numbers consistently.

Developer interlocks

In photography, you never get something for nothing. Every time you increase quality in one area, you lose it in another. Nothing better illustrates these interlocks than a discussion of fine grain ...