The basics

ADVANCED PHOTOSHOP ELEMENTS 5.0 FOR DIGITAL PHOTOGRAPHERS
Spreading the pixels >> In the example, the digital
fi le has dimensions of 800 x 1200 pixels. Though the
number of pixels remains the same, each of the prints
ranges in size because of the numbers of pixels used
to print each inch.
(a) 16 x 24 inch printed at 50 pixels per inch (ppi).
(b) 8 x 12 inch printed at 100 ppi.
(c) 4 x 6 inch printed at 200 ppi.
(d) 2 x 3 inch printed at 400 ppi.
Pro’s Tips:
• Know where you are going before you start the journey – your scanner
resolution should be based on the end use of the digital fi le. A poster will need a
higher resolution initial scan, and a bigger fi le, than a postcard.
• Balance print quality with practical fi le sizes – test your printer to see at
what image resolution increases in print quality cease to be perceived. Make this
your base image resolution and scan your fi les according to this setting.
Once you know the image resolution needed for the printer, the fi nal size of the print and the size
of your original you can easily calculate the scanning resolution and the total pixel dimensions
you need for your digital fi le. Use the formula in the table below to give yourself an indication of
the number of pixels you need for any size print job.
Pro’s Scanning Resolution Formulae
1. Final image dimensions
( pixels)
= Original image dimensions
(inches)
x Scanning resolution (samples per inch)
3000 x 2400 pixels = 10 x 8 inch print x 300 samples per inch
6000 x 4000 pixels = 1.5 x 1 inch (135 mm fi lm) x 4000 samples per inch
2. Print size (inches) = Image dimensions ( pixels) / Image resolution ( pixels per inch)
15 x 12 inches = 3000 x 2400 pixels / 200 pixels per inch
20 x 13.33 inches = 6000 x 4000 pixels / 300 pixels per inch
Book resources at: www.adv-elements.com
17
SCANNER AND
CAMERA TECHNIQUES