When someone says the word photography the first thing that most people think of is pictures. People never think of what goes in to the developing process. They do not think about all the chemicals that go into developing the pictures. Many people just wonder why their picture came back with nothing on it or why they look like a ghost. They do not even bother to think about all the chemistry that goes on to develop the pictures. They think of how much money they just wasted on a bunch of messed up pictures. If they were to sit down and think about all the chemicals that went into making that ne picture they would view it differently.
Photography is just another form of chemistry when it comes down to it. In the year 1864 a chemist by the name of Joseph Wilson Swan produces the first way to develop film. (Joseph). What was known as the auto type process was created by using a gelatin film soaked in carbon or other pigment granules. This process would then be photosensitized by using potassium dichromate. Later in 1879, he produced the bromide printing paper that we now use in standard photographic medium. Since photography has been around for about 100 years the chemicals sed to make both motion pictures and still pictures are the same.
Both motion and still photography share many similar chemicals such as fixers, developers, and stop baths. Also from the very beginning the durability and stability of pictures has been a problem. The fine-grained and superficial silver, the paper and plastics as base, the gelatin, albumin as binding agents, which was found in many black and white photos were affected greatly by the environmental conditions. It was not in till 1935 that Kodak came out with the first color film. That was the birth of modern day film. The durability of the color film though was orse then the black and white.
With the color dyes and no longer the metallic silvers the colors were under the problems of the environment. They had to be put under sun light, chemical agents, heat, and moisture. Then when the pictures where stored wrong the colors also got bleached out. It is virtually impossible to restore the original photo. (AWP) So now the goal of these people who are trying to restore these black and white photos is to reproduce the original colors of the bleached photo instead of restoring the original dyes. Not only do we face the problem of faded photographs we also ace the problem of having to fix scratched or dusty films.
In order to remove the scratches a classical liquid gate printing method gets used. The liquid gate is applied to both sides of the original film. The liquid fills the scratch and reduces the light scatter. When processing film most photographers prefer to use black-and-white film because of how much easier the development process is. When you develop the photographs you need to have developers, stop baths, fixers, washing aids, wetting agents ,water, film cleaner, reducers and intensifiers, and paper. (Davis) Each of these agents have there own purpose to be used.
Many of the chemicals also come in liquid or powder form. There are two kinds of developers; one for film use and one for paper. (Davis) The most common developing agents are hydroquinone, Metol, and phenidone. (Photographic) Some other developers that are not as common are Amildol, Benzotriazole, Borax, Chlorquinol, Glycin, Hydroquinone, and Kodalk. Developing agents are to weak to work alone so they must work with an accelerator. The accelerator is used to activates the developing agent. When you mix a developer with a strong accelerator you will get a quicker developing time and higher contrast.
The quicker accelerator also has bad side effects like excessive fog, soft emulsions, course grain, and shorter developer life. The most typical accelerators are; sodium hydroxide, sodium carbonate, Kodalk, borax, and sodium sulfite. When using the developer and accelerator you also want to use a restrainer. The restrainer is added to reduce the chemical fog, the chemical fog is caused by an unexposed silver halide crystals. The restrainer also is used to slow the developing action in areas that receive less exposure. Most restrainers are potassium bromide and benzotriazole.
After the developers the next step would be to dip the picture into a stop bath. (Davis) The most common stop bath is made of 28% acetic acid, which is usually diluted before use. The stop bath is used to stop the action of the developers and it also helps to prolong the life of the fixers. Another stop bath that can be purchased is a stronger form called Glacial Acetic Acid. This acid is extremely toxic and is not recommended for use. Many stop baths contain certain chemicals that change colors to tell you when that stop bath is becoming exhausted.
Many people will substitute water for the stop bath ut by doing this they are not stopping the action of the developer. That is a common mistake mad by many people. The fixer, also called the hypo, is used once the developer has developed the image. (Davis) Some fixers that are commonly used are Boric acid, Formaldehyde and sodium sulfite. (Photographic) The fixer is used to stabilize the image, but it to must be washed away. (Davis)
If you leave the fixer on for to long it will eventually cause staining or fading of the image. Photographic) If used correctly the fixer is to dissolve the undeveloped silver halide crystals from the film or paper. If you are using poor paper they will stain due to the darkening of the silver halide crystals. Most fixer contain a fixing agent, it is the most active part of the fixer in removing any undeveloped silver halide crystals. It also contains acid such as acetic acid. This stops the developing action usually when no stop bath is used. A preservative is also included, it is used to prevent disintegration of the fixer by the acid.
The fixer also includes a hardener and buffer. The hardener is usually used in film development to keep it from softening and scratching. When it is used on prints it causes spotting and toning. The buffer, usually boric acid, is used to keep the acidity of the fixer if a hardener is used. The washing aids and wetting agents are now brought into play after you have used your fixer. The washing agent is used after your fixer instead of having to wash it for 30 minutes to remove al fixer residue, you get to quickly treat it in a washing aid for five to ten minutes. (Davis).
The wetting agent is used on and only for film. Once your film has been washed you want to give it a quick treatment in your wetting agent to ensure that it dries evenly. Once you have your picture developed you can use a toner. The toner changes the tone of your finished prints. (Davis) The toner is used to darken your black and white photo to a shade darker or more. (Photographic) You can also use the toner to tone out the spots in a image. The most common toner used is Potassium Ferricyanide.
When photographers go to set up there dark room they usually set up a wet and dry side. Davis) They usually do this so when working with the wet side, the chemicals, they will not risk getting their already developed pictures ruined. Just by touching a developed picture while you have a little bit of a chemical on your fingers can ruin it. When working in your dark room you want to be sure that you have no light leaking into your room, the leaking of light into the room can cause the film to get exposed before you are ready to treat it with the chemicals. Silver halide is a term used to explain to combination of silver and a halogen element. (Photographic) A few halogen elements are bromine, chlorine or iodine.
The silver halide crystals respond to the light that is reflected off of the image. The silver is affected more by the lighter areas because of how they reflect light unlike the dark areas which absorb the light. Many silver alide crystals have very distinctive six-sided shapes. When developing the photographs these crystals either get developed or they get washed off of the picture during either the stop bath or after they developed photo has been fixed. An alternative development of film would be emulsion. (Photographic) Emulsion is a gel that is stored at room temperature, in order to use it you must heat it to 110* in order to liquefy it.
When you go and pour the emulsion in to a container to use you want it to also be heated other wise the emulsion will solidify. Once you have your emulsion poured so you can use it you want to pread it evenly on to your papers, you want it to spread out evenly. Once the emulsion is spread evenly you want it to dry, you need to put the piece of paper that you have coated with emulsion into a safe dark place where no dust particles will get embedded on it. After you have dryed your paper you can begin to print you picture on it. Photographic)
To develop your emulsion you go through the same steps you used for your black and white photos. Be sure that you use a hardening fixer, preferably in powder form. You would then need to rinse the photo for ten minutes at the least to remove all the excess chemicals. When working with mulsion you want to use hand coated papers and fresh chemicals. When handling photographic chemicals you want to be wearing goggles, an apron, gloves, and an organic vapor respirator. (Photography) When working in your dark room you also want to have and air change at least ten times an hour.
They also recommend that you have exhaust ventilation for processing and mixing tanks. When working with these chemicals they tell you that you should never add water to acid you should always add acid to water instead. (photography) You should also avoid and products that contain benzene. Doctors have found that benzene if inhaled can cause cancer. When storing your chemicals you want to make sure that they are out of the reach of small children and pets. (Photography) When storing acid you want it to be placed in a nonmetal unbreakable container.
All other chemicals should also be placed in non-breakable containers and then placed inside of another plastic container. All of your diluted solutions should be marked clearly with the date you mixed it and whet chemical it is. This helps so you will not use any outdated chemicals. When it comes to disposal you want to make sure that all unmixed chemicals are disposed of through a licensed hazardous waste handler. Photography) If you are unable to get a licensed waste handler you can go through a professional household hazardous waste collection. It is better if you are able to use up all of your chemicals.
When you no longer need your left over chemicals before throwing them away you should check with local schools, professional photographers, or ever photographic materials suppliers to find out if they want your unused chemicals. After checking with local agencies and finding that they don t need your left over chemicals then you should go about throwing them away the proper way. Hopefully now when people hear the word photography they will not hink of only the bad pictures they get back from Wal-Greens or K-Mart, but they will think of all the time and effort that people put into developing those pictures for them.
People should think of photography as something fun to do in their free time but they also need to remember all to the chemistry that goes in to developing their photos. They also need to realize all of the chemistry that went into making the roll of film that they are using in their fancy cameras. Every one should know bout the developers, the stop bath, the fixers, the washing aids, the wetting agents, and all of the toners that are used to develop hat one single roll of film they used.
But when using chemicals people must also remember that you must use safety and protection. When handling photographic chemicals you must have all skin covered, you must wear goggles, you need to wear a breathing mask and you must also wear gloves. When you are using chemicals you also want to be sure that you dispose of them the proper way. You should never flush or pour chemicals down the sink or toilet. So not only is photography something to do in your free time but its chemistry, as you develop pictures you are learning chemistry.