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Basic Darkroom Techniques: Developing B&W film
The following are step-by-step instructions for developing your own B&W films. The basic equipment and chemicals are relatively inexpensive and simple, except for the enlarger. When it comes time to printing, if you don't have an enlarger, you can rent one usually for a reasonable rate. (most universities and many high schools have darkrooms, and some companies rent time in darkrooms)Background - What happens during the process
When you expose film to light, by opening the shutter, the light reacts with the light-sensitive silver-halide particles in the film emulsion. At this point, the reaction is invisible. The film must be developed in order for the reaction to be visible. The film is developed using a chemical developer, which turns the exposed silver-halide particles into a black metal (silver). The film stays in the developer for the correct time to turn the right amount of halides into silver. The dark areas in the original image will have the least amount of silver on the film, and appear transparent. The lighter areas, conversely, will have the most silver. This effect is why the developed film is called a negative. In order to stop the development process, a stop bath is used. It neutralizes the effects of the developer. At this point the film is developed, however the image is not permanent, there are still unexposed silver-halides in the emulsion. If these particles are exposed to light, they will turn into silver quickly. The film has to be made permanent, this is done with a chemical fixer. The fixer attaches itself to the unexposed silver-halides, preventing them from reacting to the light. The final stop is to remove all traces of the chemicals in a wash step. If fixer is left on the film, it will eventually stain the image. There are additives, like Kodak Hypo Clearing Agent, which can speed up the wash process. After washing, the film must dry.Processes
MixingSetting up to Develop
Loading the Film
Preparing to Develop Black and White Film
Developing Step
Acid stop bath
Fixer
Wash
Drying
Storing
Note: For developing film, you don't need a darkroom, you can do it with a changing bag, or even a light tight closet, because once the film is in the processing tank, you can work in any amount of light.
Mixing
You'll need:- Running water (Water Supply)
What about water quality?
- Chemical Manufacturer Specification sheets
- Place where you can mix liquids (Sink)
- Measuring Beakers or Graduates
- Very accurate thermometer, and possibly a method of Temperature control
- Stir sticks
- Funnels
- Maybe a water filter
- Storage Bottles
- Developer
- Stop Bath
- Fixer
- Measure a certain amount of water at a specific temperature - it's usually easier to have the water hotter than the required temperature and let it cool down, or even use an ice cube to lower the temp (remove the ice cube when the water reaches the right temperature)
- Measure a certain amount of concentrate (or powder) or use the full amount in the packet.
- When the temperature of the water is exactly the specified temperature, pour in the concentrate (or powder), stirring constantly.
- When the concentrate is completely disolved, add water to make a certain amount
Use the thermometer during the mixing of chemicals to make sure that you are following the manufacturers recommendations. After mixing, store the liquid chemistry, and make the next solution. Sometimes, you mix up a storage concentrate, and sometimes you mix up a working solution. By this, I mean that you have just mixed up a solution that you do not use without diluting prior to use. - but this is not true for all chemistries - read the labels. Label each of the bottles you've just made, with:
- The chemical
- Whether it's a concentrate or working solution
If it's a concentrate, record the dilution to use when making the working solution
- The date mixed, and the expiration date
- The volume of chemical mixed
- The expiration quantity (working solutions only)
Fixer for example, will indicate in the manufacturers materials sheet how many sheets of 8x10 paper, or how many rolls of 36 frames of 35mm film can be processed prior to expiration
Setting up to Develop
Gather together:- A film processing tank. I have two stainless steel tanks, one holds one 35mm reel, the other holds two reels. Some people prefer plastic reels. If you get a tank which holds two reels, you aren't required to develop two at a time, you can develop just one.
- A pair of scissors, to cut the film.
- Measuring graduate(s), to measure the correct amount of chemicals for your film.
- Containers to hold the mixed chemicals - one for developer, one for acid stop, one for Fixer
- An accurate thermometer, to determine the temperature of your chemicals and the correct developing times.
- Film clips or wooden spring-type clothes pegs, to hang your film to dry.
- A can opener to open your film canister.
- An accurate timer to time your processing - this can be a watch with a second hand.
- A changing bag or light proof room or closet.
- A water-bath - a tray which can hold at least 1 inch of water and your chemical containers and film tank
- Developing chemicals - Developer, Acid Stop, Fixer, water
Loading the Film
For this step you need: Film processing tank, reel(s), film, scissors, darkroom or changing bag.- Before trying to load film in darkness, practice loading your reel in light with an old piece of film. Do this until you can do it with your eyes closed.
- Put the tank, reel(s), film and scissors in the darkroom or changing bag.
- Check that the room is dark or the bag is closed.
- Open the film canister with a can opener.
- Pull the film out of the canister - it's wrapped around a spool - if you've practiced you know this, and know what it feels like.
- Try to touch the film only on the edges - try not to touch the emulsion.
- Trim the end of the film square - cut across the film at a 90 degree angle to give you a straight edge.
- Hold the reel in your left hand with your thumb in the center of the reel, with the spiral turning outward clockwise from your thumb (if you are left handed you may want to reverse the hands and the rotation directions)
- Hold the film in your right hand, the spool of film held loosely between your little fingers and palm, and the film as it comes off of the spool between your forefinger and thumb (don't worry if the spool drops to the floor, unless you have a dusty floor!)
- Gently squeeze the film between your right thumb and finger, it should curve slighly across the width of the film. It should curve upwards - as long as the spool is feeding over the top (counter clockwise) through your fingers.
- Push the end of the film into the center of the reel - some reels have a spring clip to hold the film in place, some do not, I prefer the ones without the clip.
- Maintain the gentle squeeze on the film as you rotate the reel slowly counter clockwise, gently feed the film into the reel. When you practice this you can see that the film is settling in the coils of the reel. Note how this feels so you can tell if you are doing it right in the darkroom.
- Continue until you reach the end of the film. Cut off the film at the spool - if you can feel tape on it, try to cut just enough off of the film to not get tape in the reel - it isn't that important however.
- Continue sliding the film onto the reel, until it is all on the reel.
- Find the two notches on the reel - where the film is fed into.
- Slide the film into the reel at the two notches, until it is past the ball bearings - at that point the film will not out.
- Holding the sides of the reel in each hands, twist one hand then the other, this will pull the film onto the reel.
- If the reel is clean and dry, the film should wind on easily. Keep winding until you get to the end of the film.
- Cut off the film at the spool - if you can feel tape on it, try to cut just enough off of the film to not get tape in the reel - it isn't that important however.
- Continue winding the film onto the reel, until it is all on the reel.
- Put the reel in the tank, and put the lid on the tank - even if you are doing more than one reel of film - why? so you don't forget and inadvertantly open the door when someone knocks - trust me.
- When all the reels are in the tank you are ready to develop the film. You can turn on the light, or remove the tank from the bag at this point.
Preparing to Develop Black and White Film
For this step you need: Loaded tank, chemicals, water-bath, thermometer, chemical containers This is the critical step in developing Black and White film. Using the wrong amount of chemicals, or the wrong temperature or time will adversely affect your film. Most developers have an optimum temperature, I prefer to develop at that temperature, rather than adjust the time based on the temperature - it gives more consistent results. Stated another way, if you adjust the time based on a change in temperature according to the manufacturers chart, don't expect to get exactly the same results. If you want to experiment - pushing or pulling - do so by changing the time, not the temperature, until you've truly exhausted the experimentation.- Set up your water bath, a tray, or baking pan, or some other container that can hold your measured out working solutions (developer, stop, fix) and the film tank, and have room left over for about a quart of water - put the tray on the counter or in the sink, and fill it with about 1 inch of water. Adjust the temperature of this water to reach the developing temperature.
You can use hot and cold water to adjust the temperature, or hot rocks and ice cubes, or just about anything you can think of. For this entire process you will be checking the temperature in this bath (using your thermometer) about every 5 minutes, and adjusting as you go to maintain the correct temperature. - Put the loaded tank into the water-bath.
- Mix the chemicals according to the manufacturers instructions. Pour the correctly diluted solutions into the chemical containers - make sure you have the right amount for your tank - it's listed on the instructions, or measure it with water to see how much you need to cover the reel(s).
- Put the chemical containers into the water-bath.
- Adjust the temperature of the water, and allow the temperatures of the chemicals to stabilize at your desired temperature. (Usually 20°C or 68°F)
It is best to use the same temperature every time, for consistency, rather than adjusting the time for different temperatures.
Developing Step
- When the developer and film are at the right temperature (because they've sat in the water bath for a few minutes)
start the timer.
If you are using a darkroom timer, then set the time to be the development time plus the fix time, plus 2 minutes, 30 seconds for the stop bath, twice 15 seconds to drain chemistry, and the first minute is used to wait until the second hand reaches 0
- The next time the second hand reaches the top of the timer, pour the developer into the tank through the hole in the inner lid and then put on the outer lid. The tank should be in the water bath, at the correct temperature.
- Agitate.
There are many schools of thought on agitation, and it can lead to heated debates. Generally there are four kinds of agitation. I call them invert, twist, bang, and rotate.
- Invert. Turn the tank upside and return it to right side up.
- Twist. Twist the tank one direction then back the other way, about 180 degrees each way, you should hear the reel turning inside the tank.
- Bang. Tap the tank on a hard surface - helps to dislodge any air bubbles.
- Rotate. Put the tank in a machine that keeps the tank rotating throughout the process.
- Continue agitating at regular intervals throughout the developing stage. I agitate for the first 30 seconds, then
each minute thereafter, at the top of the clock for about 10 seconds.
I believe the most important part about agitation is to do it the same way every time. Many people say I agitate too rigourously, but it's the way I started, and I do it consistently.
- Check the temperature of the water in the water bath, and adjust as necessary, between each agitation cycle
- At the end of the time, based on the manufacturers recommendations to start with, later you will refine your developing time, remove the outer cap (ONLY!) and pour the developer out, either down the drain with running water or into a bucket for later disposal. (developer makes a good fertilizer)
Yes, and yes. But it's really not that important, first the time pouring out is just about the same as the time pouring in, so they offset each other, second, you will eventually adjust your times to suit your equipment and style, and third, the difference made by 5 or 10 seconds is very slight.
Acid stop bath
- Pour the acid stop into the tank, through the hole in the inner lid, then put the outer lid on. The tank should still be in the water bath. Usually at this time, it's 15 seconds past the end of the developing time.
- Agitate. I agitate continuously for 30 seconds. When twisting, the tank is in the water bath. But don't forget to invert and bang.
- Remove the outer lid, and pour out the chemicals. After this, it's usually 1 minute past developing time, so the remaining time is all fixer. Pour the acid stop down the drain or into the same bucket you are using for the developer (acid stop is weaker than vinegar, or lemon juice).
Fixer
- Pour the fixer into the tank, through the hole in the inner lid, then put the outer lid back on.
- Agitate. I agitate for about 20 seconds, then every minute for about 10 seconds.
- Keep the tank in the water bath between agitating, and keep the water bath at the correct temperature.
- At the end of the manufacturers recommended time, remove the lid (it's now safe to remove the whole lid if you want), and pour out the chemistry.
Wash
- Remove the inner lid.
- Run water into the tank. I like to run water for about 15 seconds, then put the reels into my film washer.
- Either replace the water in the tank every minute for the recommended time, or leave the film with water running over it for the recommended time. Pour the fixer either down the drain or into the bucket. (the fixer is the only chemical I'd be concerned about disposal of, because it contains the silver, however in the small quantities of a hobby darkroom, it may not be a problem - just don't tell anyone I told you so. Your local codes may not allow it.)
Drying
- Empty the tank, and fill with wetting agent (Kodak Photo Flo, diluted correctly).
- Put the reel(s) in the wetting agent according to the recommendations (30 seconds).
- Turn off all fans. Don't blow dry films. Dry your film in a dust free area.
- Remove the reel from the tank.
- Slowly pull the film off of the reel, clip one end to an overhead cord.
- Pull the rest of the film off of the reel.
- Weight the bottom of the film, with another clothes pin, or film clip.
- With a damp sponge, ever so gently, remove any water droplets. I slide the sponge down the film, barely touching it. Be careful to not scratch the negatives, they are very soft at this point.
- Check to see that all the fans are off in the room.
- Leave without stiring up any dust.
- Return in about 3 or 4 hours.
Storing
- Remove the weight from the bottom of the film.
- Using scissors cut of the leader on the free end. I leave the top clipped to the line while I'm doing this so that it doesn't fall on the floor.
- Count up 5 frames, cut between the 5th and 6th frame. 5 frames fits across an 8" sheet of paper, and fits into negative sleaves.
- Put each strip into a seperate negative sleave.
- Label the sleave with the year and roll number (sequential)
- Keep cutting into 5 frame lengths until you've cut the entire length of film.
Visitor Comments
The comments stated below are not necessarily the opinions of Andy Hughes or DarkroomSourceI am a student using your site for information about darkroom techniques for a science project. This was a good resource for me to find instructions on how to develop, but it would've been helpful if you had a special place to tell me what chemicals exactly are used in darkroom developing. It may have been here but i couldn't find it anywhere. Just a suggestion. Thanks.Anonymously contributed on 2004-03-04 16:31:43
Generally an acid stop bath is not necessary for film, it is sometimes harmful if the developer used quite a bit of carbonates. Plain water works fine and will sometimes improve shadow detail.Contributed by on 2004-04-08 08:13:43
The film should be washed for 10 to 15 minutes in slow running water. It should then be rinsed once or twice in distilled water. This is to remove dissolved salts that may be in the water supply. Then the film should be treated in Photo-Flo for 1 minute. This greatly decreases the chance of water spots on the film.
I\'m a senior and at our shool we have to do senior project (on photography development)and the information that you have really helped me a lot so thatnks.Contributed by on 2005-10-06 14:10:55
This was a great source of information for an art class project, thank you very much.Contributed by on 2008-02-11 09:19:20
iam in photography at my high school right now and this web site was a huge help. but i would like to see how you take your film that you developed and make positive prints out of it.Contributed by on 2008-11-12 20:51:29
Id like to know techniques used in softening a printAnonymously contributed on 2009-02-15 16:52:42
This page really helped me alot with my sr. project. so thanks. (=Contributed by on 2009-11-01 18:44:52
