Developing Film (8455.38, 41, 43, 48 / 8415.58-61 / 8418.58-61)
CHEMICALS There are three basic chemical solutions needed to develop exposed black and white film.
1. Developer – The developer changes exposed silver salts, which cannot be seen, into black metallic silver salts, which can be seen.
2. Stop Bath – Stop bath is a weak acid solution used after the developer. It neutralizes or stops the developing action.
3. Fixer – After the film has gone through the developer and stop bath solutions, the image can be seen. However, it is still light sensitive and opaque. Fixer dissolves all remaining unexposed silver salts in the film emulsion. After fixing, the film will no longer react to light.
THE PROCEDURE The easiest way to develop film is in a developing tank. A developing tank is a light-tight container made of plastic or metal. Exposed film is wound onto a reel in complete darkness. 1. Loading the film in the developing tank: A film change bag is used to load film into a developing tank. To use the film change bag, place all needed equipment into the bag, tank, reel, film cassette, and scissors, and then seal the bag.
Open the film cassette. Slide the film spool out of the cassette and cut off the film leader if needed. Roll the exposed film onto the tank reel and cut the spool off of the end. When handling film, do not touch the surface of the exposed film. Once the film is loaded onto the reel, place the reel into the developing tank and lock the lid in place.
2. Film Developing: Film development can be broken down into a six step process with an elapsed time of less than 30 minutes. (If you do not have at least 25 min. of class time to complete this process, DO NOT start!)
The steps in developing black and white film are as follows:
1. PRE-WET -1 MINUTE – Pre-wetting the film allows the emulsion to soften, allowing for the developer to be absorbed consistently. 2. DEVELOPER – 5 MINUTES. Agitate the tank during these 5 minutes. (Factors like type and speed of film will determine your developing time. Time varies for each type of film. ) When done, pour into disposal bin.
3.STOP BATH - 30 SECONDS – After the developer has been discarded; pour in ten ounces of stop bath. At the end of the thirty seconds, pour the stop bath back into the original container.
4.FIXER - 5 MINUTES – Pour ten ounces of fixer into the tank. Agitate the same as the developer. Fixer can also be reused. At the end of the five minutes. pour the fixer back into the original container.
5. RINSE - 5 MINUTES – When you have poured out the fixer, immediately wash the film by placing under running faucet (or by pouring 10 oz. of water, agitating then changing water) for at least five minutes.
6. WETTING AGENT - 10 SECONDS – After the film has been thoroughly washed, a wetting agent such as Kodak Photo-Flo can be added to the water. The wetting agent prevents water from beading on the film and forming watermarks. When done, pour wetting agent back into original container.
3. Drying
After washing, the film may be removed from the tank reel and hung to dry. Be sure to hang a clip on the loose end to prevent film curl. (Put your name on the clip, so you know which one is yours!)
After you finish developing your film, rinse all developing tank parts and dry them so that others may use them.
Once the film is completely dry, cut the negatives into convenient lengths (3 to 5 exposures) and store them in a negative sleeve.