How to Use the Crop Tool in Photoshop CS6
To crop an image in Photoshop Creative Suite CS6, use the Crop tool. When you select the Crop tool from the Tools panel, you automatically get a crop box at your image’s edges, which appears as a dotted line with brackets at each corner and rectangles at each side. You can refer to these as handles.
Note that you can also drag around the part of the image you want to keep and then release your mouse button.
The area outside the cropbox appears darker than the area inside in order to better frame your image. Adobe calls this a shield. You control the color and opacity (the amount of transparency) of the shield by adjusting the settings on the Options bar. Click on the Set additional Crop options button (gear icon).
If, for some strange reason, you don’t want the shield, deselect the Enable Crop Shield check box in the panel. The Auto Adjust Opacity option enables you to hold your mouse down to temporarily reduce the opacity of the shield.
Version CS5 gave users an added aid in framing images with crop overlays of Grid and Rule of Thirds. Version CS6 includes these in the View options pop-up menu located on the Options bar. The following list provides a brief explanation of each view overlay:
Rule of thirds: A photographic principle that advocates placing elements most appealing to the eye at one of the four intersecting points of the rule of thirds grid.
Grid: A grid equally divided into squares within the crop box.
Diagonal: Another type of grid with larger squares positioned diagonally. This overlay can help to identify diagonals in your composition that are dynamic and interesting.
Triangle: A grid comprised of four triangles. Like diagonals, images that use triangular compositions are visually interesting.
Golden Ratio: A compositional principle, used by artists throughout history that is based on a rectangle that can be divided into a square and a rectangle. The resulting rectangle is known as a golden rectangle. If you subdivide that rectangle into a square and rectangle, you once again get another golden rectangle and so on.
The ratio itself works out to 1:1.618. You can crop your image into this golden rectangle. Also within the rectangle, the intersection of the two diagonals or in the very center is a great spot to put your focal point. Interestingly, the Rule of Thirds is really a simplified version of the Golden Ratio.
Golden Spiral: Another compositional principle used by artists throughout history. Instead of a rectangle, it is a spiral where the growth of the spiral (as it gets larger) is the golden ratio — the spiral gets wider by the value of the golden ratio for every quarter turn.