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Any ideas for a photography science fair experiment?


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<p>You could always try developer dilution vs development times and the effects on negative contrast. Yes it will take time, but any project worth doing is worth doing properly. Or you could chart the relationship between development temperature vs time to achiece uniform negative density. There's tons of others out there, pH of water for a given developer vs development time for uniform negatives, etc., etc.</p>
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<p>Procure from the web some Farmers Reducer. This is a two part solution, bleach plus fixer. Farmers Reducer is used to lighten negatives that are over-exposed or over-developed. The bleach part is potassium ferricyanide. Sounds dangerous but the cyanide is too tightly bound to iron, and therefore has super low toxicity. It was, for years, the bleach of choice for color films and papers. It’s the best for what I am going to describe, however its replacement now in use in the C-41 color negative film process is EDTA. You could procure some C-41 film bleach for this task (not Blix which is EDTA plus fixer). After the beaching has completed, about 4 or 5 minutes, wash and dry. </p>

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<p>Make a batch of black & white prints in the darkroom. We are talking silver based gelatin prints. You know, the prints you develop, stop and then fix and wash. Immerse the finished black & white prints in the potassium ferricyanide solution (Farmers reducer part A). This step is performed in normal room light. The image on the paper will disappear. It’s not gone, just chemically changed back to a silver salt that is about the same shade as the print paper. </p>

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<p>Now for your science project: Demonstrate how black & white prints are developed in the darkroom. Only, you are going to do this in normal room light. Prepare four trays. Tray 1 is your usual paper developer. The other trays are for show, they can be stop, fix and water or all can be water with some yellow food dye added for show. </p>

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<p>For your demonstration, immerse a previously beached and washed paper print in the developer tray. Swish it about to agitate. You will see the black & white image reappear. As this is happening, tell your audience the science of film and paper developing. Look all this up and prepare a lecture. You can email me for the dialog. <br>

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Best of luck!<br /></p>

 

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<p>Back when there were still dinosaurs I got an honorable mention -- the "smart kids" won the prizes. I explained the developing process for film and paper with samples at various stages, and displayed a mini darkroom setup with enlarger, trays, etc. I explained camera obscura, steps in the advance of photographic process, early days till then, '59 or '60, I think. I built an adjustable color wheel with the motor from an erector set that you could align and spin to get different color results based on proportions. Talked about the properties of light, can't recall all of it. Interactive was the big thing that worked for me. </p>
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<p>Or a little more specific on the developing process: How does water pH affect the performance of developing agents? If you need a limited topic stick with one developer (like D-76, Rodinal, HC110, etc.) You will need to borrow a pH meter (make sure it is calibrated). You'll need several samples of water to mix your developer and use distilled water as a control.<br>

A broader approach could be to compare the effects of low pH on a few different developers. </p>

 

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<p>A good science fair project conducts a scientific investigation. You start with a question you want to answer. (Does a stop bath make a difference?) Then, you make a hypothesis statement of what might happen. (Stop bath will result in less development resulting in lighter negatives.) If you want to get more elaborate, include additional hypotheses about the effect of a your change (stop bath) on other attributes like graininess and sharpness. Before you start, you should have a way to test you hypothesis. (Make identical exposures. Develop wth and without a stop bath. Compare negatives.) Then run your test and find out if your hypothesis is correct. It's ok if it isn't. The next step is to propose a theory that explains your results and propose a test to confirm your theory. </p>

<p>If you have access to a densitometer, you can measure the optical density of the negatives. If not, put the negatives on a light box and look at them. If the difference is enough to make a difference, you will be able to see it. </p>

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  • 1 month later...

<p>cyanotypes !<br>

cheap, easy, as photographic as silver prints, can be done anywhere there is light, no darkroom needed<br>

youcan get paper precoated ( or coat your own ) you just need water to process,<br>

as safe as it gets, can remove some or all of the "blue" with a dilute water and baking soda mixture<br>

kid-proof, loads of fun<br>

chemistry used: potassium ferricyanide and ferric ammonium citrate and water<br>

http://www.alternativephotography.com/wp/processes/cyanotype/cyanotype-classic-process</p>

<p>good luck !<br>

john</p>

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