The combination of Photoshop and the iPad is, at least in theory, a perfect match. Though practice can make a mouse or trackpad and keyboard feel intuitive, there’s something about physically manipulating an image with your fingers that fits like a glove. Unfortunately, though Photoshop Touch is easily the most advanced photo-editing tool on iOS, usability issues make it fall short from being a serious photo editing tool.Photoshop Touch has been available for Android tablets since October, but it just launched for iPad last night. It features many of the staples of Photoshop, including layers, filters, effects, gradient fills, and much more. On paper, it isn’t far removed from Photoshop Elements, the quality consumer-level version of Photoshop for PCs.Photoshop Touch’s feature set is powerful enough that it could be a legit photo editing app, but this only makes its shortcomings that much more obvious. The biggest issue is in making selections. The key to working with layers is being able to make a clean selection of part of an image. Photoshop and Photoshop Elements both excel with making selections. Photoshop Touch doesn’t.In addition to the Magic Wand tool and Marquee tools of various shapes, Photoshop Touch gives you a scribble-to-select tool that you would think would make the process even easier than it is on a PC. Unfortunately, this isn’t the case. As you can see in the below video, selecting part of an image becomes an exercise in tedium — and still yields a flawed result:Photoshop Touch simply can’t determine the edges of a selection nearly as well as desktop Photoshop can (including Elements). In the above video, 30 seconds of monotonous scribbling still can’t yield a clean selection of the iPhone. My attempts to clean up the selection by zooming in and using other tools (like polygonal lasso) weren’t much more successful. Photoshop Touch’s edge detection algorithm just isn’t what you’d expect from Adobe.There are other issues too. Precision painting or selecting is hindered because the brush is smaller than your finger, leaving you unable to see the precise edge of the brush. Also, the app limits the file size to 1600×1600, and won’t save layers (no PSDs, only JPEG). So once you save your project, it’s case closed.Make no mistake: the toolset in Photoshop Touch is, on the iPad, second to none. The layout and UI can be picked up quickly by anyone who is accustomed to Photoshop, though it could be confusing for beginners. Unfortunately, due to the mediocre performance of the selection tools, those beginners are the only people who can get much use out of Photoshop Touch right now. The app has great potential, and I look forward to future updates that bridge the gap with the PC versions. But, right now, this is more of a novelty for casual image editing than anything that can be used by even semi-professionals.Photoshop Touch costs $10 in the App Store. It requires an iPad 2 (sorry, O.G. iPad owners) running iOS 5 or higher.