While Photoshop Lightroom is great for organizing photos, processing images, making slideshows, and printing, it’s not Adobe Photoshop. Lightroom can’t handle special effects, photo retouching, pro-level sharpening, or one of the bazillion (yes, bazillion) things that Photoshop does. Many times during your workflow, you’ll need to jump out of Lightroom to "do some Photoshop stuff" and then jump back to Lightroom for printing or presenting. Luckily, these two applications were born to work together.
Assume that you’ve made all the tonal changes you want in Lightroom. Now you’re ready to do things that Lightroom just can’t manage. For example, in Figure 1 I’d like to remove the white line on the right side of the photo, hide some distracting little things on the car itself, add a zoom effect, and sharpen the photo significantly. For this kind of work, it’s time to jump over to Photoshop. From the Lightroom menu, choose Photo > Edit in Adobe Photoshop CS2 (or CS3, if you have that), or use the keyboard shortcut Command-E (PC: Ctrl-E).
Figure 1 Photo courtesy of Dave Moser.