It happens all the time: you want to shoot a photo of something in a hurry, and it’s not straight. Back in the days of film, you’d get your prints back from developing and look at them, and if you wanted them straightened out, you’d have to use scissors. Fortunately, it’s a simple process now. In Apple’s Photos app, you can do this in a few clicks.
Here’s an example. I was on the grass in my garden taking pictures of Rosalind the Cat, and I got a few of her walking toward me. You know that cats won’t sit still, so they were all a bit skewed. This isn’t a problem when the background is less obvious, but here, with the house behind her, it looks a bit odd. (Though some people might actually like that strange angle…)
First, go into Edit mode. To do this, select a photo and press Return. In these screenshots, I’m in Edit mode; you can tell that you’re in this mode because of the black background and the buttons on the right side of the window.
To straighten a photo, you use the Crop tool. In the next screenshot, you’ll see I’ve select that tool in the column of buttons at the right.
When the crop tool is active, you’ll see a frame around the image, and, to its right, a small arc showing numbers like on a clock. If you click anywhere on that arc, you can drop up or down to rotate the image. It moves as you drag, and Photos also displays grid lines to help you align the image.
As you can see above, I’ve aligned the edge of the lawn with one of the grid lines. Photos maintains the aspect ratio – the white frame – and zooms the photo so after cropping it fills the frame (you can see what’s being cropped outside the frame).
When you’ve got the angle you want, press Return and Photos applies the crop. (And it still retains the original photo, and you can revert to it at any time by clicking Revert to Original at the top of the window.)
Here’s the final photo:
Note that you can also do this on an iPhone or iPad; tap the Edit button, and you’ll see the Crop button. It works the same on iOS as on the Mac.