What is RESOLUTION?

The term Resolution is typically used to describe TWO things about a digital image:
  1. The CANVAS SIZE: The total number of "Dots" or "Pixels" that the total area of the image takes
  2. The OUTPUT RESOLUTION: How tightly packed together the "Pixels" are programmed to appear when finally printed
    1. This is expressed as "Dots Per Inch" or DPI. It can also be described as PPI (Pixels per inch) or PPC (Pixels per Centimeter)


VERY Low Res
Low Res
"Screen" Res

Resolution-Happy-Faces01.png
Resolution-Happy-Faces02.png
Resolution-Happy-Faces03.png
Canvas Size:
20 x 20 px
40 x 40 px
200 x 200 px
Output Resolution:
9 DPI
18 DPI
90 DPI
Total Pixels:
400
1600
40,000
Filesize:
Very very Low
Very Low
Low

Photoshop stores BOTH of these "measurements" under IMAGE - IMAGE SIZE
  • "Low Res" images
    • Use relatively few pixels that are loosely packed together (ie 20x20 pixels @ 9 DPI)
    • Can be stored in VERY small file space
    • Can appear very crude, jaggy or blurry if enlarged
  • "High Res" images
    • Use MORE pixels to record higher detail
    • Require much more file space
    • Can appear smooth if displayed at their ideal output resolution

Typical Media Resolutions
_Filler100.gif
Media

_Filler100.gif
Canvas Size
_Filler100.gif
Output Resolution
Computer Screen
1024x768
90 DPI
IPod Touch
480x320
163 DPI
4x6" Photograph
1200x1800
300 DPI
11"x17" Poster
2200x3400
200 DPI
More can be found on the Wikipedia

When creating a new Photoshop "Canvas" - you need to choose your RESOLUTION first
Photoshop_New01.png
You are asked to define the RESOLUTION
  • CANVAS SIZE: Define the HEIGHT and WIDTH in pixels (note - you may need to change the units from inches to pixels)
  • Define the output resolution in "Pixels per inch" (also known as PPI or DPI)
  • The COLOUR MODE should be set as "RGB colour"

If you understand all this, you're ready to try the Happy Face exercise