skrwt, perspective fix, lens distortion, iphone, iphoneography, mobile photography

Let’s face it. Despite significant improvements in the iPhone’s camera, it still has a perspective problem. The prestidigitation required to make its tiny 4.16 mm focal length take good-looking pictures is impressive, but but artifacts from its tiny focal length still show up in the form of odd lens and perspective distortions.

SKRWT (pronounced “screw it” … really) is a great utility that corrects those perspective and lens distortions. The app is currently $1.99 and should be a part of every iPhoneographer’s toolbox.

It quickly and easily helps to fix the perspective lines and angles in your photographs so that they look more natural, symmetrical, or at least more visually appealing. For more on perspective, see Misho Baranovic’s excellent post on perspective distortion and correction.

After loading your photo, the app uses a sensitive and accurate analog-style dial to rotate and adjust the image on either the horizontal or vertical planes. While it doesn’t let you adjust both planes at the same time, you can easily adjust one axis, then the other. I found the dial to be extremely responsive. You can also tap the edges of the dial for even more precise adjustments.

Using the same dial interface, you can also level a photo’s horizon. I really like SKRWT’s straightening tool and think it’s one of the best available on iPhone. It’s set pretty loose allowing you to make precise straightening adjustments. The tool is not sticky at all which I’ve found to be an issue with many other apps.

The crop tool is pretty slick. Its eight handles make it easy to use and make pretty precise crops on the small iPhone screen. It features several standard preset aspect ratios which adapt to portrait or landscape photographs. There’s a free ratio crop setting for everything else — always handy for non-standard crops.

Lens Barrel Distortion Fix

SKRWT also has a tool which helps to fix or reduce the curved distortion created when using many of the inexpensive magnetic mount iPhone wide angle lenses. It’s a stable and versatile tool. There are several adjustments which reduce several types of distortion from a variety of iPhone lenses, including third-party wide angle, fish-eye lenses, and a special setting with an algorithm especially for GoPro cameras mounts.


If you’re looking for an Undo button, there isn’t one. SKRWT uses a very slick non-destructive workflow. Edits are not applied until the image is saved. You can go back to any adjustments and change them at any time.

Your results will vary based on the quality of the original and the amount of adjustment needed to bring the image true. Often though, SKRWT’s corrections are striking. It does a great job straightening the curves created with a wide angle lens. It’s also very impressive when correcting fish-eye lens photography. SKRWT needs to slice off a few pixels around the edge of your image to work it’s magic. But by using a combination of perspective fixing and content aware tools, it’s able to save a surprising amount of the original image that might otherwise be cropped out using other apps.

Instead of reducing the size of your image, SKRWT resamples your photo back to its original size with few, if any, artifacts. Another detail that I really like about SKRWT.

The Bottom Line

The app is fast, responsive, and rock solid. It never crashed once during my tests. All of the tools are simple to use yet very powerful in their precision. Overall, SKRWT is an excellent utility that belongs in your toolbox. It quickly and easily corrects several of the lens-related issues found with the iPhone’s camera. It’s a part of my regular iPhoneography workflow and I highly recommend SKRWT.


App Store Link: SKRWT – mjagielski



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Fast, responsive, and rock solid. An excellent utility that belongs in your toolbox.

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