Lightroom allows you to open and edit your photos in Adobe Photoshop, Adobe Photoshop Elements, or another photo-editing application. Lightroom automatically uses Photoshop or Photoshop Elements as the external editor if you have either application installed on your computer. You can also specify an external editor in Lightroom preferences.
When you open a photo from Lightroom directly in Photoshop CS3 or later, you have several options. You can edit the photo in its current format, or open it as a Smart Object. You can also merge a series of shots into a panorama, merge to HDR, or open two or more photos as one layered image in Photoshop. When you save edits to a photo in Photoshop, Lightroom automatically imports the new photo into the catalog.
To edit a photo using Photoshop or Photoshop Elements from within Lightroom, you must have one of those applications installed on your computer. Then follow these steps: