Apple Aperture Digital Photography Fundamentals - Manual (Page 37)

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Understanding Resolution
The concept of resolution often confuses people. Cameras,
displays, and printers measure resolution in different ways.
Resolution describes how much detail an image can hold. This section explains image
resolution and shows how understanding image resolution can help you create better
digital images.
This chapter covers:
 Demystifying Resolution (p. 37)
 How Resolution Measurement Changes from Device to Device (p. 40)
 Mapping Resolution from Camera to Printer (p. 41)
 Calculating Color and Understanding Floating Point (p. 43)
Demystifying Resolution
An image’s resolution is determined by the image’s pixel count and the bit depth of
each pixel.
Learning About Pixels
A pixel is the smallest discernible element in an image. Each pixel displays one color. A
pixel’s color and brightness range is determined by its bit depth. For more information,
see “
Learning About Bit Depth ” on page 38.
Pixels are grouped together to create the illusion of an image. On color displays, three
color elements (one red, one green, and one blue) combine to form a pixel. As the
number of pixels increases, the image’s detail becomes sharper, more clearly representing
the original subject. Therefore, the higher the pixel count, the more likely the displayed
image will look like the original subject.
Because so many pixels fit in even a small image, pixel count is often expressed in
megapixels (millions of pixels). For example, 1,500,000 pixels equals 1.5 megapixels.