Apple Macintosh PhotoFlash - Manual (Page 73)

When you define the work area’s new dimensions, the New Size figure (which
indicates what the image’s uncompressed size will be after you save it) also
changes automatically.
IMPORTANT If you increase the work area’s dimensions, it will use more disk
space when you save it. Make sure you have enough space available.
5 If you’re enlarging the image’s work area, click one of the squares in the upper-right
corner of the dialog box to indicate approximately where you want the image located
within the new work area.
6 Click OK to close the Resize dialog box and initiate work area resizing.
PhotoFlash resizes the work area.
Changing an image’s resolution
You can use the Resize command to change the resolution of a single image or
of multiple images represented by selected catalog thumbnails. Resolution is
usually expressed in dots per inch (dpi)—that is, the number of pixels in a 1-
inch-high column of pixels. An image’s resolution may differ from the
resolution at which it is displayed. For this reason, the size of an image
displayed on screen may differ from its size when printed. For example, an
image that measures 5 by 3.5 inches on a 72-dpi monitor measures about 2.5
by 1.75 inches when printed at 150 dpi.
Some printers and other devices produce better results if the images they
print are set to a specific resolution. For best results, follow the directions
regarding resolution in the documentation that comes with the printer or other
output device. The general rule of thumb is that the image resolution should
be no more than half of the printer’s resolution, as suggested by this table.
For the best results in: Set the image file resolution to:
Displaying images on computer screen, like desktop presentations 72 dpi
Printing images on most laser printers (300 dpi) 150 dpi
Printing images on higher-end laser printers (600 dpi) 300 dpi
Creating image output for film production 600 dpi
Printing on very high end print production printers 2400 dpi
63 Manipulating Images