Most Fridays since we started the Able Pear blog (over two years now), we have shared a set of iPhone wallpapers: 320x480 portrait images that also work on the iPod touch and the Palm Pré. We love doing this and call it iPhone Fridays.
The Friday before Apple's iPad launch, we started producing iPad wallpapers in parallel with the iPhone wallpapers using the same images but at a much higher resolution: 768x1024, the resolution of the iPad screen. Up until then we did not have an iPad to view them on. The next day we all picked up our iPads. The images were beautiful but there was one exception I had not anticipated even though I've seen it in over and over in the media hype; the iPad can be in any orientation.
The images that we had created were nice but when you rotated the iPad from portrait (tall) to landscape (wide) the image was scaled up 133% to fill the width of the device.
Later that week I created a PNG file in Illustrator to load on my iPad to visualize how the device was presenting the image in the background. I knew that the highest resolution was 1024 pixels and the smallest was 768 pixels and that I would have to create an image that was 1024x1024 so that I would fill the iPad's screen in any orientation without scaling the image.
We can also see that the "always" viewable image area is 768x768 in the center of the 1024x1024 image. The upper and lower parts of the image are presented in portrait and the left and right are seen when in landscape, but the image itself is not scaling the fit the screen.
So this is my conclusion: iPad wallpapers need to be 1024x1024 to accommodate both orientations. Okay, that's a given, but now I'm left with a new question: What's up with the corners and if they are never presented then should you omit the image data from the wallpaper to save on file size? After all, adding the corners up, that's 128 pixels by 128 pixels, times four.
What are your thoughts? Keep the image data intact or delete the corners and save it as a 24-bit PNG? If you're making iPad wallpapers, will you use 1024x768 or will you adopt the larger square format? If you are an iPad owner what would you rather download? Let us know and we'll see you on iPhone Friday. Cheers!