This has been a problem that has bugged me for sometime.

When you want to export images for the iPad, you would head in lightroom for the export menu, set your parameters and voilà: go and collect the output. All fine — until I realized that some images appeared less sharp on the iPad screen when set as background.

See, the form factor of the iPad screen is 4x3, but the form factor of most DSLR camera detectors is 4.5x3. That means that when you export your images onto 1024 pixels in the long edge (iPad size), you get images that are too short in the height (683 instead of 768 pixels). I wouldn’t care to see the empty pixels filled in with black — but that’s not what the iOS software does. It somehow re-scales the pixels, and in some cases images loose sharpness :-/

The solution is shown in the screen shot below. I cropped the image to a factor of 4x3, *then* export to 1024 pixels in the long edge. Perfect.