Apple added a very cool 3D parallax effect to the iOS 7 Home screen and Lock screen, which lets you look at what’s “behind” your home screen icons when you tilt your iOS device. Details of how the effect work are laid out in this post, but its basically iOS magnifying your wallpaper to give it space to move around when you tilt your device.

To make the 3D parallax effect look even better, you can use a slightly higher-res image so that when iOS zooms into the image to create the extra margins to move around, the image pixels end up being mapped 1:1 on the screen.

Here’s the demo of the parallax wallpaper in action:

http://youtu.be/ljoy4iAQwWw

The folks at Trusted Reviews did the math, and it turns out that for wallpapers to look perfect with the parallax effect, you need to add 200px extra on each side of the image. Here are the sizes you require as per your device:

• iPad 2 and iPad mini: 1,424 x 1,424
• iPad 3 and iPad 4: 2,448 x 2,448
• iPhone 4S: 1,360 x 1,040
• iPhone 5: 1,536 x 1,040

Note that the iPhone 4 doesn’t support 3D parallax wallpapers.

• To create these wallpapers you’d ideally want to start with an image size larger than the ones mentioned above.

• If they’re in the same aspect ratio as the final resolution, just resize the image to the appropriate dimensions based on your device, else you’d need to crop your image to get it to the desired aspect ratio, and then resize.

• Once you’re done, save the image and set it as your wallpaper.

Here’s a video walkthrough of how to make your own parallax wallpaper in iOS 7:

As always, let us know how it goes in the comments below.