ByMarilyn J. Ellis
Photoshop is a comprehensive package that can intimidate a beginner, but taken step-by-step, it can be easy to learn, especially if each new skill builds on the one just mastered.
Raster vs. vector images
Photoshop, up until version 6.0 which was released in September 2000, used raster imaging. Drawing with a pencil or painting with a paintbrush places the color exactly where you put it, and except for undoing, erasing, or redrawing, you cannot change it. This differs from a vector package, such as Micrografix Draw or CorelDraw, which produces points and connecting lines that can be moved or reshaped as desired. You have the option of changing your initial drawing. It was not possible to create vector items in Photoshop before version 6.0.
To use Photoshop, students must first understand what pixels, or rasterized images, are and how to work with them. Pixels are points of light displayed on the screen that represent the graphic image being drawn. In simplest terms, pixels are on or off, black or white.
Pixels are measured per inch, or “ppi.” The resolution or sharpness of the picture increases as the number of pixels increase. Seventy-two ppi is fine for an image to be viewed only on a screen, but if the piece is to be printed, a minimum of 300 ppi is required. Increase in resolution means that each pixel is much smaller in size.
To teach the manipulation of pixels, start students with a plain black and white bitmap file. Below is an example of a tutorial for a beginner. The objective is to add to and take away from the object until it is cleaned up and looks like the drawing in Step 6. This is a basic skill the student can use right away on the job.
To introduce my students to this basic concept, I give them a piece of black and white artwork that needs cleaning up. These are the steps to do so.
Select the white area with the Magic Wand tool. Hold down the shift key and click on each area in white until you have selected all areas. (Notice the dashed lines around all the white areas.)
Now choose Select/Inverse. Now you have the black area selected instead of the white. (Notice the dashed lines now only around the black areas.)
Use the Magnifying tool to get close enough to see the pixels. This improves accuracy in cleaning up a selection.
Next, with the Lasso tool, hold down the shift key, and drag an area around the section you want to add to the selection. (The alternate key will deselect the area.)
Now choose the Paint Brush tool, choose black for the color, and paint in the selected area. In order to select one pixel, use the Pencil tool, choose Windows/Show Brushes, and choose the smallest pencil size.
Finally, continue to choose areas, paint them in, or erase them until you have a cleaned up image as shown to the left.
This exercise introduces students to many of Photoshop’s important selection tools that allow the user to highlight and change part of a drawing. The Magic Wand tool selects areas of similar colors, the Marquee tools select boxes and circles, and the Lasso tool lets the user draw a free-form shape.
Once an area has been selected, the student can mask it by pressing the Mask button at the bottom of the Toolbar. Masking part of an image allows a user to change its attributes or delete it entirely.
You can paint over holes in the mask with the Paintbrush and deselect areas with the Eraser. Once the mask is complete, it can be saved for future use. It can also be inverted to select the rest of the drawing, or it can be turned off completely.
This tool is great for retouching photographs because it replicates details such as tree leaves and paints them precisely—with hue, color, and texture intact—into a new location.
To use the Rubber Stamp Tool, click on the area you want to copy, hold down the alternate key, and click on the area you want to paint. The image will transfer photographically, preserving textures in a way that painting, filling, or airbrushing the area cannot recreate.
A foundation of skills
This tutorial explains a specific use for each tool, but the tools have many other uses. There are also many other ways to accomplish these same effects. Graphic artists are always finding new ways to use this tool and your students will also. Your goal is just to get them started.
How do you go about teaching this application? Do you have a stash of sample files that you give to students to work on or that you use to illustrate certain techniques? Send us your tips for teaching Photoshop so we can share them with other readers.
Marilyn J. Ellis, MCSE, has a master’s of science in occupational education with a specialization in training and development. Her experience also includes classroom and online instruction of data communications courses at Tomball College, Tomball, TX.