Activity: How does a
Picture Develop on Photo-paper? |
Optics: Expose Photo-paper
/ Develop Pictures |
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Target group: children of 5 to 6 years in kindergarten |
Aim: Discover the principle of exposing photo-paper, develop pictures |
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Where? A group-area that can be blacked out; a photo
laboratory |
How long? Approx. 2 hours |
What? Distinguish
photo-paper from „normal“ paper, expose photo-paper, develop pictures
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Preparation: |
Steps: The children tell the
difference between photo-paper and normal paper by touching and feeling the
surfaces (information #1). In the dark photo-lab, the
children put different objects on the coated side of the photo-paper,
(information #2). The children expose their
photo-paper one after the other for approx. 20 – 30 seconds (information #3). Afterwards, the exposed photo-paper is fastened to a clothes pin and
put into the three plastic-bowls, one after the other. First into the
developer, then into water for rinsing and finally into the fixer. Since your skin should not come in contact with the chemicals, the
photo-paper is fastened to the clothes pin. When putting the paper into the
respective baths, the photo-paper is steadily and easily waved back and
forth, (information #4). The photo-paper (the pictures of the items), are hung up to dry on a
clothes line. The „photos“ thus made are displayed or used for decoration. |
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Scientific Explanation: Information 1: The photo-paper has a special, coated surface, that
contains substances which are sensitive to light. Information 2: Since photo-paper is photosensitive, we can only make
pictures in dark rooms. Information 3: The exposure causes a chemical reaction on the spots of
the paper that are not covered. Information 4: A chemical reaction makes the exposed spots on the
photo-paper turn dark and almost black depending on the length of the bath in
the developer. In the water bath, the photo-paper is rinsed, and in the
subsequent bath in the fixer it is made durable. |
Possible Variations: The room is not blacked out. The entire photo-paper turns
black. Instead of different items, developed films are used. What you get are
contact prints. |
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Attention!
The developer and the fixer are damaging to your health! In case of
contact with skin rinse the liquids off immediately with cold water. After use the developer and fixer should be poured into separate
containers and kept for re-use. The remaining used liquids should not be poured down drains (ie
toilets or sinks), but must be disposed of by an expert. |
Sources: |
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