Over the years, Lightroom has matured into a sophisticated and powerful photo cataloging and editing application. Lightroom 2 added improved Photoshop integration, the Graduated Filter Tool, the Retouch Brush, vignettes, and more. Lightroom 3 upped the ante with improved importing, video support, lens corrections, sharpening and noise reduction, the Grain feature (a film grain effect), postcrop vignettes, custom watermarks, and the Slide Show module.
In addition, version 3 brought the same high-quality RAW file processing engine as found in Photoshop. Now at version 4, Lightroom has grown even more powerful with a new processing engine, a Book module, a Map module, Soft Proofing, and additional video features...
Read the REVIEW: Adobe Photoshop Lightroom 4 in Reviews. - Comments (Reply To Topic)