Overhead Transparency

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Overhead Transparency

• Terminology

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Understanding a few basic terms is helpful in
utilizing the overhead projector.
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Basic Vocabulary Used with Transparencies

• Aperture
• Base Cell
• Overlay
• Fixed Sequence
• Random Sequence
• Mask

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1) Aperture
This is the window in a transparency mount the
area through which light passes and is thus
projected onto the screen.
The inside of the mount is called the APERTURE.
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2) Base Cell
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3) Overlay
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Fixed Random Sequence Overlays
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Fixed Sequence
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4) Mask
Cardboard or opaque paper taped to the front of a
transparency frame is called a mask. There are
different kinds of masks.
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Types of Masks

• Area Mask
• Controlled Reader Mask
• Circular Mask
• And More

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Mask System

• Area Mask

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Mask System

• Controlled Reader Mask

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Mask System

• Circular Mask

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Some More Masks
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Mounting
Step 2
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Mounting (continued)
Step 4
Step 5
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Attaching Overlays
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Attaching Overlays

• Start with a 1-inch piece of tape.
• Mentally divide it into fourths.

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Attaching Overlays

• 2 quarters stuck together, 2 quarters stuck to
  overlay.
• 6. Repeat step 1 to 5.

3. Affix ¼ to the overlay, then fold tape in
half. 5. Staple to mount.
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Your Turn!
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Separating Images