Introduction
Start Here
In this book, you will be working your way through a full course curriculum that will expose you to all of the essential features and functions of Adobe Photoshop. Along the way, you’ll learn the concepts and vocabulary of digital images. Between several larger projects are chapters of lessons. In those lessons, each action that I’d like you to try looks like this:
- This is what an action looks like.
The paragraphs surrounding the action explain some of the why and how. For greater depth, the second section of this book is a Compendium of those features and functions, providing the “deep dive” needed for true mastery of this powerful application. Throughout the Course section, I will suggest readings in the Compendium section. Although you may be able to complete the entire course without them, I think if you do those readings you’ll find yourself regularly nodding and muttering, “oh, that’s why it works that way.”
Software and Files
Have you installed Photoshop yet? If you work for a company with an enterprise license, it’s likely your IT people have installed it for you. We will be using the Creative Cloud app as our hub for launching Adobe applications and accessing the services that come with a Creative Cloud (CC) license. This app also checks to make sure your software license is up to date, so it should remain running whenever you use your creative applications. I use the CC app’s Preferences to have it launch on startup and auto-update software so I don’t have to worry about it.
I most often launch Photoshop by clicking the Open button below the Photoshop icon. If there’s an update available, it’ll be available in the Updates section.
To follow along with the projects and lessons in this book, you’ll need the files. Launch your favorite web browser and go to rockynook.com/photoshopCandC, answer a simple question, and download the files. Put them somewhere convenient (and memorable).
Image File Formats
Raster and Vector
Digital image files fall into two major categories: raster images, those composed of pixels, and vector graphics, which use geometry. The majority of the files you will use in the course are raster images. We will also use a few vector graphics, made in both Adobe Illustrator and Photoshop. Since we’ll be spending so much time with pixels, however, it’s best to know just a little bit more about them before we start our lessons.
The word “pixel” stands for “picture element,” and the idea to use many small elements to compose a picture is an ancient one.
If we have enough pixels, packed together tightly enough, we can believe we see an image. Electronic displays use this principal and so does imaging software. The measure of the pixel density in an image is called its resolution, and it is measured either in pixels per inch (ppi) or pixels per centimeter (ppcm), depending on where you live. I apologize to my readers outside the United States, but I will most often use pixels per inch.
Some use the word “resolution” a little differently. When referring to video or displays, some will refer to the number of pixels across the width or height of the device. For example, “1080p” refers to images and devices that are 1,080 pixels tall, and “4K” refers to those that are approximately 4,000 pixels wide. I call this a measure of “pixel dimensions.” If you stand too close to a 200-inch 4K display, the image may look more like the mosaic above than a pleasing image. That’s because its resolution (its density) is only 20 ppi. But the 27-inch 4K display in front of me now has a resolution of almost 150 ppi, rendering this text very sharply.
Photoshop users may care about both definitions. Web and interface designers worry about the proportion of a screen an image will occupy, and thus pixel dimensions play a large role for them. Those who print require a high density of pixels to look pleasing.
If an image has too many or too few pixels, it can be resampled. Photoshop possesses several algorithms from which we can choose to achieve results with the highest fidelity. There are frequent updates and improvements to this process so beware of old advice. Don’t tell anyone, but we can often reliably double the resolution of some images, or more. The results are not as good as starting with an image of that many pixels, of course, but if we’re lucky, few will notice.
File Formats
There are many file formats to choose from when saving your work from Photoshop. The choice depends on the needs of your recipient and what kind of data needs to be preserved. Most of these formats hold only raster data, whereas SVG and PDF can hold both raster and vector data. Also, one can include data in these formats either by opening them directly in Photoshop or by “placing” them, usually as something called a Smart Object, which is covered in both the Course and the Compendium sections of this book.
DNG & Raw Files
Many digital cameras can save their images as raw files. Raw data is not even pixels yet!
Each sensor has an electrical charge on it. When light hits it, the charge increases: more light, more charge. A raw “image” is really a record of all those changes of charge.
Every camera manufacturer has its own proprietary raw file format—one that contains all the data recorded by the sensors. These include NEF (Nikon) and CR2 (Canon), as well as many other formats. It takes software to interpret that data as an image. Photoshop, through its plugin Adobe Camera Raw (or ACR), is precisely that software. Unfortunately, that support does not extend to adding metadata (keywords, copyright) or saving ACR edits into these manufacturer-proprietary formats. For that, there is the Adobe Digital Negative (DNG) format. Unless you use DNG, metadata is saved in an accompanying “sidecar” file or a central database—indirect at best.
Some of the files used in the course are raw files (DNGs, actually). When we discuss processing raw files, I will recommend converting your own manufacturer-specific raw files into DNG. Luckily, some camera makers have adopted it as their format.
Photoshop (PSD) & Large Document Format (PSB)
Most of the files we will use in the course are Photoshop’s “native” file format, Photoshop Document (PSD). After completing edits in Photoshop, it’s important to save your image in a format that stores all the structure and information you have added so you can access it all when you open the file later. PSD stores all of that information, including Channels, Layers, and more. PSD files also provide powerful integration features when used with other Adobe products like InDesign and Illustrator.
Photoshop PSD files can support file sizes up to 2GB. For the majority of images, this is sufficient. But in the real world of digital imaging, it is possible to have much larger files. Photoshop supports these by using the Large Document Format (PSB). This format supports all of the features of PSD files, but also supports files of any size. It is also the format used for the content of a layer type called a Smart Object.
TIFF
Tagged Image File Format (TIFF) is an industry standard. In many ways, a basic TIFF is just a big array of pixels stored in a large file, although it can also preserve much of what the Photoshop format does. Also, depending on the options chosen when saving, a TIFF may be accessible to someone who does not have Photoshop. Finally, TIFFs are typically saved losslessly. That is, no data is lost unless you specify that it is. That stands in stark contrast to the next format.
JPEG
JPEGs (Joint Photographic Experts Group) are ubiquitous because they can be viewed on any device by any user. They have file sizes that are much smaller than TIFFs, for example. Does that sound too good to be true? There is one issue: they achieve their small file sizes by discarding data. That may not be a problem for snapshots from a party, but may matter greatly for photos from a once-in-a-lifetime vacation or expensive location shoot.
We often receive JPEGs from others. So if we open and edit one, we’ll need to save it in a lossless format to arrest any further degradation. PSD or TIFF will do nicely, as we’ll see.
PNG
Unlike JPEGs, PNGs (Portable Network Graphics) can contain transparent or translucent pixels. Also unlike JPEGs, PNGs use lossless compression to make their file sizes smaller than a simple recording of the color (and opacity) of each pixel, but the result has exactly the same quality. This makes PNGs a good choice for graphics like logos that, for some reason, must use a raster format rather than vector.
SVG
Scalable Vector Graphics, the redundant name of this format, is the primary vector format that is used for web design. Although most designers create SVG files from Adobe Illustrator, you may create them from Photoshop as well. If you attempt to open an SVG directly in Photoshop (rather than place it as a Smart Object), Photoshop will ask you how it should be “rasterized,” that is, turned into pixels.
Adobe’s ubiquitous Portable Document Format is a broadly supported way to provide your documents to someone who doesn’t have Photoshop. It retains vector and raster (pixel) data. As with SVGs, opening a PDF often results in its being rasterized, becoming a simple image.
A Note Regarding Keyboard Shortcuts
To be efficient in Photoshop, or any application, we should take advantage of time-saving features like shortcuts. I will always share menu-driven ways to achieve our ends (when such exist), but I’ll encourage faster ways too. A comprehensive list of shortcuts is in the Appendix of this book. Wherever shortcuts appear, the Mac shortcut precedes the shortcut for Windows.
