In Lightroom, all the sliders in the Develop module pretty much affect the entire image at once. So, if you wanted to affect just part of an image, you’d get the Adjustment Brush and paint over the area you wanted to affect. In Photoshop, you can also do that (well, to some extent), but if you want to edit just one part of your image, you use Photoshop’s Selection tools (there is a tool for every type of selection imaginable, which is one of the things that makes Photoshop so powerful). Here are the primary Selection tools you’ll use the most:
Making Rectangular Selections:
If the area you want to select is either square or rectangular, there’s one tool that does both: the Rectangular Marquee tool (I think they call it “marquee” because the animation that shows where the boundary of your selection is looks like a Hollywood movie marquee with chasing lights, but most folks call the boundary “the marching ants”). You just choose this tool (it’s the second tool from the top in the Toolbox, or press M) and select an area to work on by clicking-and-dragging a rectangle out over that area. Now, only that selected area will be affected by whatever you do to it (as seen here, where I drew a rectangular selection between the columns. And, now, if I were to lighten or darken the image, only the area inside that rectangle would be affected).
Adding or Subtracting from Your Selected Area:
Once you have a selection in place, if you want to add more areas to it, just press-and-hold the Shift key and drag out more rectangles. That’s what I did here, where I selected the areas under the left and right columns by dragging out smaller rectangles. If you want to subtract an area from your selection, press-and-hold the Option (PC: Alt) key instead and click-and-drag over that area (which is what I did on the sides and very bottom of the columns). (Note: You can use these keys to add/subtract from selections made with any Selection tool.) Now that all those areas are selected, I brightened them by going to Photoshop’s Levels command and dragging the Highlight slider to the left, as seen below (more on Levels later).
Deselecting & Square Selections:
If you want to remove your selection altogether (called “deselecting”), press Command-D (PC: Ctrl-D). If you want to make a square selection (rather than a rectangle), just press-and-hold the Shift key, then click-and-drag out your selection and it will be perfectly square (as seen here). Once again, any changes I make will now just affect that selected square area, as seen here, where I went to the Levels command again and brightened the highlights. (By the way, Levels is found under Photoshop’s Image menu, under Adjustments, and it lets you adjust the highlights [the white slider on the far right under the graph—drag to the left to brighten], the midtones [the gray slider in the middle—drag right to darken the midtones; left to brighten], and the shadows [the black slider on the left—drag to the right to make the shadows darker]. This is what we used before Camera Raw and Lightroom.)
Straight Line Selections:
Not every object with straight lines is a rectangle or a square, but there’s a tool for that: the Polygonal Lasso tool (it’s nested beneath the Lasso tool; press Shift-L until you have it), which lets you draw a selection made up of straight lines (for example, if you wanted to select a stop sign or a yield sign, you’d use this tool). It kind of works like a connect-the-dots tool: You click it at the point where you want to start, move your cursor to the next corner and click, it draws a straight line between the two points, and then you continue on to the next point. When you get back to where you started, click on the first point again and it creates the selection (that’s how I selected the column on the left here. I started at the top-right corner and worked my way around, and then I brightened the highlights with Levels).
Drawing Freehand Selections:
The Lasso tool (L; the third tool down in the Toolbox) lets you draw a freeform selection like I did here, where I selected the open archway in the background. You just click and start drawing, like you’re tracing around the edges with a pencil or pen. When you get back to near where you started, just release the mouse button and it connects back to where you started and it makes the selection. I also went to Levels here and darkened the shadows.
Using the Quick Selection Tool:
If you want to select an object, like the vase you see below (or is it a pot?), you’d get the Quick Selection tool (W; it’s the fourth tool down in the Toolbox) and just paint over what you want to select (like I did here, where I painted over the vase), and it selects it by sensing where the edges are automatically (this is similar to the Adjustment Brush in Lightroom with Auto Mask turned on). (Remember: You can add and subtract from any of these selections that we’ve talked about—just press-and-hold the Shift key to add to your existing selection or press-and-hold the Option [PC: Alt] key to remove areas from your selection.) Here, I also went to Levels and increased the highlights.
Using the Magic Wand Tool:
We use this tool much less today than we used to in the past (mostly thanks to the Quick Selection tool), but it’s still handy when you have a solid color or similar colors in an area you want to select. For example, if you had a solid yellow wall and you wanted to select it so you could change its color (using the Hue slider in Photoshop’s Hue/Saturation adjustment, found under the Image menu, under Adjustments), then the Magic Wand tool would be the tool that would usually select that entire wall in one click. In our example here, we want to select the green trees outside the arch in the background and use Levels to darken the shadows. So, take the Magic Wand tool (it’s nested beneath the Quick Selection tool; press Shift-W until you have it) and click it once on the trees. It gets most, but not all of them, so press-and-hold the Shift key (to add to your current selection) and click it again over any areas it missed on the first click. You might have to do this a few times. Also, the Tolerance amount (up in the Options Bar) determines how many colors out it selects. The higher the number, the more colors it includes, so if it selects way too much, just enter in a lower number (I lowered it to 20).
Inversing a Selection:
A popular selection trick we use when making a tricky selection is to select something easy in an image (like the vase, here), and then go under the Select menu and choose Inverse. This inverses the selection, so everything but the original object we selected is now selected. So, for example, if we wanted everything in this photo to be black and white, except for the vase, we’d select the vase, choose Inverse, then go under the Image menu, under Adjustments, and choose Desaturate. I thought showing you this, here, might come in handy at some point.