Lesson 7. Photoshop Concepts

This is the first lesson in Photoshop, intended to help you learn about how bitmap/pixel based images work. My approach to teaching Photoshop is to not show you the coolest effects, but the inner workings of how the program works. You will see similarities between the user interface of Illustrator and Photoshop.

Topics for this week include:

Points: 40 (+ 8.33 participation points)

Estimated assignment time: 4 hours

Due: Friday, February 23, 11:59P

7.1 Comparing Bitmap Images to Vector Images

Our study of Illustrator included the understand that the images we created consisted of a dot-to-dot method of constructing images with line segments drawn between. The difference between vector based artwork and what we refer to as bitmap images is significant. When we are discussing bitmap images we are referring to images comprised of pixels. Think of pixels as small squares which when put together form a images. If I provided you with a stack of bathroom tiles and asked you to create an images, you would stack these in a grid to form a pattern. Several quiz/exam questions will come from this discussion. Lessons include:

Disregard any references to dates/times and due dates mentioned in the videos. Follow the due dates listed here.

7.2 Making Selections In Photoshop

In this portion of the lesson we concentrate on the selection tools and how they work. By using selections, you can make edits to a pixel based image and only affect specific areas. This is a key lesson in our understanding of Photoshop. Lessons include:

Disregard any references to dates/times and due dates mentioned in the videos. Follow the due dates listed here.


There are numerous sources online to help you understand concepts presented.
Here is an online resource which explains not only the 3 basic tools from this week,
but additonal methods of selections we will get into. Check these out and be sure to share any of your sources in the online community for
participation points. View the video: 8 Ways To Get the Selection You Want in Photoshop here.

7.3 Color Modes and File Size

Changing an images color mode affects the file size. When we add or subtract data from a file, it's file size will change. In this lesson, you will view the demo video on how this works. Lesson includes:

  • Notice 3 channels of data in the RGB file.
  • See how removing the color data and saving as a greyscale results in a smaller file.
  • See how changing color mode from RGB 24 bit to CMYK 32 bit changes file size.
  • See how converting the greyscale color mode to bitmap mode results in a smaller file size.
  • videoWatch Video | 9:33 minutes

Disregard any references to dates/times and due dates mentioned in the videos. Follow the due dates listed here.

7.4 Do It!
Practice Making Selections

The beauty of making selections is that you may perform alterations and or corrections to specific areas of a bitmap image. In this lesson, you will practice using the selection tools discussed in 7.2 to see how these tools work. Experiment with the marquee selections, lasso selections, magic wand and the pen tool path. Lessons include:

  • Go online and find three images to work with. These can be of any subject, preferably something you like or enjoy.
  • Using the marquee selection tool.
  • Using the lasso tool (and the addition of the OPT/ALT key).
  • Using the magic wand tool.
  • Using the pen tool to make a path to create a selections.
  • Adding and subtracting from existing selections (using the SHIFT key to add; the OPT/ALT key to subtract).

Practice on the three separate images. Experiment with all the methods of making selections shown above and in the 7.2 video. Consider filling the shapes selected with a fill, or use the move tool to relocate the selected area of the image.

Do ItPractice the lesson, then save your three files.

Do a SAVE AS, select .jpg format is the save dialog box and name the three files with your name (i.e. - RonA.jpg, RonB.jpg, RonC.jpg).

7.5 Post an example of your work and comments to the Google+ online Community

After you have completed the assignment, visit the course's Google+ online community and post your comments about the assignment. I am also asking for you to post an image of your work on the Google+ site as well. Pick one of your three images created using the selection tools to post/discuss. The online community only accepts .jpg files. Along with your upload, describe anything new you discovered, issues you had, or comments on your experience. Post comments on your classmates work as well. Visit the Google+ online community here. Once you have posted, copy the link from the Google+ site. Go the Learning For Life portal, and paste the link in the text field and attach your three .jpg files. Hit submit.

7.6 Review and Checklist for the Week's Lesson Assignment


Grading Check List

read color modes/gamut .pdf
review image of additive and subtractive color models
watch color modes video
watch making selections video
watch "8 Ways To Get the Selection You Want in Photoshop" video
watch color modes and file size video
practice changing color modes
practice using the selection tools discussed and save three files to submit
post a single example of your favorite of the selection images and discuss on the Google+ community
submit your three .jpg files via the Learning For Life portal and provide the link to your post
complete quiz 7 on Learning For Life portal


Testable Items

  • How much data does a greyscale image with 256 shades of grey contain?
  • When viewing images on a computer, which color space are we seeing?
  • To add to an existing selection, which key do you hold?
  • Which of the selection tools makes selections based on color and tonal similarities?
  • Which of the selection tools makes selection based on hand drawn shapes?
  • Which color modes is also referred to as 24 bit color?
  • A CMYK image contains how many 8 bit channels of information?
  • Which of the color modes is typically used for high quality commercial print?
  • Which has the larger range of color gamut, the human eye, RBG or CMYK?
  • Can a vector path be used to make a selection?