1. Understanding Resolution &
Digital Cameras
Ann Ware
Bald Knob High School
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2. Resolution
 Understanding digital cameras requires that
we know how resolution works.
 Resolution is determined by how many pixels
(picture elements) or dpi (dots per inch) are
available.
 The image you see is simply a grid of
small squares or circles filled in with color.
The more squares or circles—the sharper the
image.
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3. Measuring Resolution
 Resolution is measured
by the number of
horizontal pixels times
the number of vertical
pixels
◦ Example: 3072 x 2304
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4. Megapixels
 The quality of a picture is measured by its
resolution—how many pixels it has; the
current measurement is megapixels
 A megapixel is a grid containing one
million pixels (one million squares of
color)—technically, that is an image with a
resolution of 1024x1024 pixels
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5. Resolution
 With computer graphics, there are three
different resolutions to consider:
◦ the image’s resolution (pixels)
◦ the monitor’s resolution (pixels)
◦ the printer’s resolution (dpi)
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6. Image Resolution
 The image’s resolution is measured in pixels.
 Most cameras allow you to change the resolution
before you take the picture.
 The higher the resolution—the clearer the image—
the bigger the file size.
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7. Monitor Resolution
 Monitor resolution is measured in horizontal and
vertical pixels
◦ Example: 800 x 600
 If an image is taken at 1024x768, but your monitor
can only display 800x600—that’s as good as it gets!
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8. Printer Resolution
 Printer resolution is measured in dpi—dots per inch.
 The quality of the printed image is going to be
determined by both the resolution of the image AND
the resolution of the printer.
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9. Other points to consider
 When purchasing a camera, you should also
research the following specifications:
◦ Storage Capacity
◦ Transferring Images
◦ Power Source
◦ LCD vs. Optical View Finder
◦ Zoom
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10. Storage Devices
 Memory Card
 Internal Memory (RAM)
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11. Storage Capacity
 The number of pictures you can take before
sending them to your computer is determined
by two things:
◦ the resolution of the image
◦ the type of storage
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12. Transferring Images
 Card reader
 USB cable
 Bluetooth
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13. Power Source
 Regular Batteries
 Rechargeable batteries
◦ Alkaline
◦ Nickel-metal hydride (NiMH)
◦ Lithium-ion (Li-Ion)
 AC
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14. LCDs vs ViewFinder
 LCD—Pro’s  View Finder—Pro’s
◦ Shows you the exact image  Uses less battery
that will be recorded
◦ Easy to view … delete  Easier to see images in
images, etc. bright light
◦ Displays menu
 LCD—Con’s  View Finder—Con’s
◦ Drains battery—uses ½ life  Shows close approximation
of battery of the final image—not the
◦ Difficult to see in bright light real thing
 Difficult for some people to
see
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15. Zoom
 Optical zoom actually enlarges the image—
measured in X
◦ example: 8X—increases an image 8 times
 Digital zoom takes a portion of an image an enlarges
it electronically; the image loses resolution when the
camera enlarges it; also measured in X
 Macro allows you to take close-up pictures of
objects that are small and enlarge them so they
appear larger.
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