Understanding Resolution &
Digital Cameras
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ResolutionUnderstanding 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 ofsmall squares or circles filled in with color. The more squares or circles—the sharper the image.
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Measuring Resolution
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Resolution is measured by the number of horizontal pixels times the number of vertical pixels◦Example: 3072 x 2304
MegapixelsThe 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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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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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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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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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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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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Storage Devices
Memory CardInternal Memory (RAM)
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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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Transferring Images
Card reader USB cableBluetooth
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Power Source
Regular BatteriesRechargeable batteries◦Alkaline◦Nickel-metal hydride (NiMH)◦Lithium-ion (Li-Ion)
AC
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LCDs vs ViewFinderLCD—Pro’s◦Shows you the exact image that
will be recorded◦Easy to view … delete images,
etc.◦Displays menu
LCD—Con’s◦Drains battery—uses ½ life of
battery◦Difficult to see in bright light
View Finder—Pro’s Uses less battery Easier to see images in
bright light
View Finder—Con’s Shows close approximation
of the final image—not the real thing
Difficult for some people to see
ZoomOptical 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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