Shaped Selections with the Marquee Tools
There are two marquee tools: the Rectangular Marquee and the Elliptical Marquee. With one selected, you can click and drag on the image to create a rectangle or ellipse. To create a square, hold down the Shift key as you operate the Rectangular Marquee; to create a circle, hold down the Shift key as you operate the Elliptical Marquee.
By using the Style options on the option bar, you can create a selection of a fixed size or a fixed aspect ratio. A fixed aspect ratio selection is useful, for example, if you want to print a photo at a particular size. To make a print of 4×6 inches, make a selection of the area to print by setting the aspect ratio to 4×6. The Fixed Size option requires that you set the width and height of the selection in either pixels—such as 100 px—or inches, such as 4 in.
The Elliptical Marquee can also be used to create a vignette effect, as shown in Figure 2. Make a selection around the portion of the image you want to highlight; then add a large feather value using Select > Feather. Choose Select > Inverse to invert the selection, select an appropriate background color, and press Delete.
Figure 2 This vignette effect is simple to create using the Elliptical Marquee.