PSC05: Cropping

There are many reasons why you might want to crop an image. The Crop Tool in Photoshop is pretty powerful and goes far beyond the normal use of just cropping an image in order to give it a different composition. But that is of course the main application for it, so let's first talk a bit about cropping to change composition.

Changing Composition

Today's digital cameras with 5 or 8 or even more megapixels give us quite some room to change and sometimes even improve an image's composition during post-processing. Cropping is for example often used to remove unwanted elements from an image, to clean up the composition and simply place a subject at a different spot in your picture.

The Crop Tool

You can find the Crop Tool in the tool box right under the lasso tool. Once selected, you'll see the Option Bar at the top of Photoshop change to reflect the possible settings of the tool, and this is the place where you can unleash its powers.

Cropping to a specified size and resolution

Have a closer look at the Width and Height settings for example. In conjunction with the Resolution box, you can easily specify a final size for your crop. Let's assume you want an image to end up 5 inches wide and 3 inches high when printed on a printer with a resolution of 300dpi. Just enter those values into the boxes in the Option Bar and perform the crop. Photoshop will automatically resize the crop area to that size and resolution.

Cropping to a specific aspect ratio

Here's a trick that you can use to get a crop to be a specific aspect ratio without resizing anything. Let's say you want an image with an aspect ratio of 3:2 - just enter 3 inches into the Width field and 2 inches for the Height, but make sure the Resolution box is empty. This way your crop will be fixed to your desired aspect ratio without any resizing actually taking place.

Saving your settings

If you found a crop setting that you feel like using more often, you can save it as a preset by first clicking on the arrow next to the Crop Tool in the Option Bar, and then clicking the little arrow in a circle on the right hand side in the list. From the menu that now pops up, select "New Tool Preset...", name the setting and from then on you can quickly use that crop setting whenever you need to, without having to type in the values again.

Perspective correction

Last but not least here is a very interesting use for the Crop Tool. You can use it to correct perspective on your pictures. Imagine you took a picture of a building and in order to get the whole building onto it, you had to tilt the camera up. This will inevitably lead to the building leaning backwards in the resulting picture.

So here's the steps to correct that, using the Crop Tool.

Step 1: Drag the crop tool over an area of the building, but don't finish the crop yet. Then with the crop selection still active, click the "Perspective Correction" box that has appeared in the Option Bar. Once this is checked, you can now drag the corners of the crop area independently. Make the selection cover a rectangular area on the building that matches the perspective.

Step 2: Now drag the handles on the top, bottom and sides of the crop selection outwards in order to cover a bigger area of your image.

Step 3: Hit the Enter (Mac) or Return (PC) key to finish the crop. You will now end up with a perspective corrected image.

Step 4: Do a "normal" rectangular crop on your image in order to get rid of any outside areas that might have shown up during the perspective correction, and you're done.

Rotate it!

And here's the last tip for this PSC. Do you have an image that is oblique and needs cropping and straightening at the same time? Once you made a crop selection, move your mouse outside the crop area and simply rotate it in the same way that you would with a free transformation.

If you have other creative uses for the Crop Tool, why not share them with other listeners in the tips from the top floor Forum?