A Photo Teacher |

Developing Film

Posted in Lecture Materials by Paul Turounet on February 17, 2010

Once the image has been exposed in the camera on film, the photograph has been made, yet nothing shows on film. The image is there, but it is what is referred to as a latent image. The latent image is an image formed by the changes to the silver halide crystals in the film’s emulsion upon exposure to light. The image is visible only after chemical development takes place.


Equipment | Materials Necessary to Develop Black & White Film

Plastic and Steel Developing Tanks and Reels

Calibrated Thermometer (left), Graduate (middle) and Timer (right)

Film Washer (left), Film Clips (middle), Kimwipes (right)

Archival Negative Preservers (35mm | 7 rows x 5 frames) and Negative Storage Box


Safety Considerations

Photographic chemicals should be handled with reasonable care. The goal is to avoid getting chemicals onto and/or into your body.

Blue vinyl gloves and safety glasses are to be worn at all times when handling and using photographic chemistry in the film processing rooms.

If at any point, you get chemicals on you, into your body or there is a chemical spill, it is important to take of the incident immediately, including washing the chemical off, and letting the instructor and/or lab instructor know to assist immediately for the safety of yourself and others in the lab.


Avoid Skin Contact

If you do get chemicals on your skin, wash immediately. Replace skin oils with a good hand lotion.

Avoid Getting Chemicals Into Eyes

If you do get chemicals in your eye, wash immediately with cool running water from the nearest source, faucet or eyewash station for 15 minutes. Get immediate medical attention after washing eye.

Avoid Getting Chemicals Into Mouth

No food or drinks should be in the film processing rooms and darkrooms. Wash hands after working with chemicals in both the film processing rooms and darkrooms, especially before eating.

Avoid Inhaling Chemicals

Film processing rooms and darkrooms are properly ventilated to insure fresh airflow.

Clean Up Chemical Spills

If a spill occurs it is important to contain the spill and notify the instructor and/or lab technician immediately to determine how the spill should be cleaned up. Clean your clothing and shoes if they come into contact with the chemical.

Dispose of Chemicals Properly

With the exception of the fixer, it is environmentally safe to dispose the film developing chemistry down the sink. Per federal, state and local environmental regulations, you are required to dispose of the fixer in the provided recycling container.


Loading Film onto Reel(s) and in Developing Tank

Set out materials for loading film, including film cassette, bottle-opener, scissors, reels and film developing tank.

The film is loaded onto the reel(s) in the dark.

Once the film is loaded onto the reels, insert reels onto the agitation rod and into the film developing tank, then proceed to close tank with filler | light-proof lid and cap.  If developing only one roll, load that reel at the bottom of the developing tank and proceed to load an empty reel at the top.

Insure that lightproof lid has been locked into a secure position before turning on the lights.


Film Developing Terms


Water wash to prepare film for development.


Chemical solution that converts the latent image (still invisible) in exposed film to a visible image.

Stop Bath

Chemical solution that stops the development of the film.


Chemical solution (sodium thiosulfate or ammonium thiosulfate) that makes a photographic image insensitive to light. Fixer, also called Hypo, dissolves unexposed silver halide crystals while leaving the developed silver image.


Final water wash to remove residual fixer from film.

Wetting Agent

Chemical solution used after wash to help prevent water spots during film drying.


To move a solution over the surface of film or paper during processing to insure fresh chemistry comes into contact with the surface.   Agitation should take place during each step of the film developing process.

Gently turn the film developing tank upside down with a slight rotation for approximately 1 – 2 seconds and then right side up. Repeat the process for the specified amount for each step.


Developing Black and White Film | Grossmont Photography Lab

Preparing to Work

  • Secure film developing room.
  • Roll film onto reel(s).
  • Load reel(s) into film developing tank.
  • Secure Light Proof Lid and Developing Tank Cap
  • Put on a Pair of Blue Vinyl Gloves and Safety Glasses.
  • Take bucket to Film Developing Chemistry location and Fill each labeled graduate with the correct proportions of working film chemistry.  Measurements are for standard 2-reel plastic developing tank.


Pre-Wash – 24 oz. tap water to be filled in film processing room.

Film Developer (D-76) – 12 oz. of chemical | the graduate will be filled with an additional 12 oz. of tap water for 1:1 dilution.

Stop Bath – 24 oz. tap water

Fixer – 24 oz. of chemical

Wetting Agent – 2 drops per 24 oz. of tap water.


  • Proceed to follow the steps provided in the Grossmont Photography | Film Development Guide.pdf that is posted in each film processing room. Only open the cap to pour and discard chemicals into the film development tank. Discard chemicals as instructed.


Grossmont Photography | Film Development Guide


How Film Processing Affects the Picture

The most important ingredient in any developer is the reducing agent, or also called the developing agent. The reducing agent frees metallic silver from the emulsions crystals to form the image.

After development, the fixer sets the image permanently on the film. It is important to fix the film for the specified amount of time to insure the film will not fog when exposed to light. Without fixing for the specified amount of time, the entire negative will turn dark when exposed to light.



It is important to follow proper film processing guidelines and handling to insure the film is not damaged. With this photograph by Robert Capa from the Normandy Invasion during World War II, the film was improperly handled and the film overheated in the drying cabinet, causing the emulsion to melt off the film base. Other problems that can occur during film development include process times, not filling the film developing tank with the proper amount of liquid, chemistry temperature, agitation technique, and inadequate washing.


Development Time and Temperature

Development time controls contrast and density.

The rate of the development changes during the process. During the initial stages of development, the action of the chemistry is slow. Once the chemistry has become immersed into the emulsion, then the development becomes more rapid for most of the development time, and then will again slow down during the end of the time.

The longer the developing time, the darker and more contrasty the negative becomes.

Developer temperature also affects development.

Most photographic chemicals take longer to work if they are too cool. If the developer is too cool, it will result in thin, under-developed negatives. If the developer is too warm, the film’s gelatin emulsion can become to soft and easily damaged as well as resulting in dense, over-developed negatives.


Exposure and Development

A properly exposed and developed negative will result in a more productive and efficient printing process. Expose for the shadows, develop/print for the highlights.


Changing the exposure will affect both the highlight and shadow areas. The greater the exposure, the denser the negative will be in both of these areas.


Changing the development time has little effect on the shadow areas, but will strongly affect the highlight areas. The longer the development time, at a given temperature, the denser the highlights will become, resulting in a contrasty negative. Decreasing the development time will result in less density in the highlights thus lowering the contrast between the highlight and shadow areas of the image. The negative will be flat in contrast.



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