Cropping in the Develop module can be used to improve an image by isolating critical content, sizing an image to a specific aspect ratio, or straightening an off-axis horizon line. Of course, like everything else in Lightroom, cropping is completely changeable at any time.
The Crop Overlay tool is located in the toolbar. (Type T if the toolbar isn't visible.) Click on the crop overlay icon (circled) and you are ready to go. Figure 4-24
There are several ways to use the Lightroom Develop module's Crop Overlay tool. You can set the crop area and then drag the image around within the stationary crops marks. You can also use the Crop Overlay tool (like the familiar Photoshop Crop tool) to frame the crop area exactly where you want it. (The Photoshop Crop tool actually crops away pixels, while Lightroom creates a non-destructive overlay.)
Standard Crop with Maintained Aspect Ratio
Here, I select the crop icon and the crop handles appear on the perimeter of the image. Figure 4-25 The lock icon is locked (circled), which keeps the current aspect ratio regardless of crop size.
Grab the handles and shrink the window as shown here. Figure 4-26 If you want, you can place your cursor inside the bounding box ...