Undoing Mistakes
Brilliant student though you may be, it's just possible that you may make a
mistake or two during the course of these lessons. Luckily for you, recent
versions of Paint Shop Pro have very powerful 'undo'
features. Edit > Undo or Ctrl-Z will undo your changes one step
at a time but you can undo up to 99 steps by using
the History Palette (turn it on with View > Palettes > History or
just press F3)!
If you want to to revert to the image as it was when it was last saved then
choose Revert in the File menu.
Save your work regularly
You should be able to produce some beautiful, high-quality work in this class
and you won't want to lose it, so save your work at least every 10 minutes
(Ctrl-S). In this way, even if your computer crashes, you can be sure you will
never lose more than 10 minutes' work...
Work-in-progress should normally be saved in Paint Shop Pro's PSP format
which will save with no loss of image quality and record all the details about the
image. However, PSP files are very large and therefore once the image is
finished you should save it in a compressed format such as JPEG. When
saving in this form, there is a small loss in picture quality - you can control
this by adjusting the balance between small file size and high picture quality -
a setting of about 7 is recommended for this class.
Use meaningful names when you save - it will make it easier for me to locate
and grade your work.
Resolution
If you were to look at a computerized image with a magnifying glass, you
would see that the image is made up of tiny squares. These squares are called
picture elements, or 'pixels' for short. Picture 'resolution' refers to
the number of pixels that make up the picture, and thus the level of detail that
the picture contains. The images that we will use in these lessons are usually
about 800 pixels wide and 600 pixels tall (note that this gives a ratio of 4:3
which corresponds roughly to the shape of a standard computer screen). The resolution of such
a picture is 800 x 600 = 480 000 pixels or about 0.5 megapixels (1 megapixel = 1
million pixels). This is a good size for learning to use Photoshop (assuming
your screen is set to a resolution of at least 1024x768), but this would
be rather large to include on a web page since it would take a long time to
download over a conventional modem connection (the jpeg file size would be about
200KB). Pictures on web pages should not normally exceed about 100 000 pixels or
about 40KB.
Pictures that are destined to be printed, on the other hand, need to have a
much higher resolution, for printers are capable or reproducing much finer
detail than computer monitors. Many digital cameras have a resolution of 2 or 3
megapixels (file size more than 1 MB), and this will give a good result when
printed even up to A4 size.
