The Adobe Photoshop Lightroom 4 Upgrade requires an existing, installed version of Lightroom 1, 2 or 3.

Adobe Photoshop Lightroom 4 software helps to create amazing images that inspire, inform, and delight. Perfect your shots with powerfully simple one-click adjustments and a full range of cutting-edge advanced controls. Craft elegant photo books, organize your images, and share them easily on social networks, in web galleries, and more—all with one fast, intuitive application.

Get Everything You Need Beyond the Camera
Organize, perfect, and share—Lightroom 4 combines all your digital photography tools in one fast, efficient application. Use powerful yet simple automatic adjustments or take detailed control of every feature, from editing to sharing.

Get the Best From Every Image
Get the highest possible quality from every pixel in your images, whether you shot them with a pro DSLR camera or a camera phone. Lightroom includes a comprehensive set of state-of-the-art tools for tone, contrast, color, noise reduction, and much more.

Share Effortlessly
Craft elegant photo books and easily share your photographs on social networks or in web galleries, slide shows, prints, and more. Lightroom 4 includes efficient tools to showcase your work for friends, family, and clients.

Adobe Photoshop Lightroom 4 software is ideal for professional and amateur photographers who want to organize, perfect, and share amazing images.

Tight Adobe Photoshop Integration
Select one or multiple photos and automatically open them in Adobe Photoshop software to perform detailed, pixel-level editing. See your results immediately in Lightroom 4.

Tethered Shooting
Instantly import and view images in detail as you shoot them with tethered capture, available for select cameras. Check the shot, the lighting, and more as you work.

Intuitive Environment
Be more productive and efficient. The intuitive environment and controls of Lightroom 4 are easy to master and let you quickly and smoothly accomplish your photography tasks.

One-click Adjustments to Multiple Images
Save time when processing many images. Apply the same Develop settings—exposure or contrast, for example—to all the photographs in a group at once using presets or syncing.

Superior Noise Reduction
Achieve amazing, natural-looking results from your high ISO images with state-of-the-art noise reduction technology. Apply noise reduction to the entire image or target specific areas.

Nondestructive Editing
Set your creativity free in a nondestructive editing environment that encourages experimentation. Your original images are never altered, and it’s easy to reverse your steps.

Superior Image Processing
Get the absolute best from your images with state-of-the-art image processing controls. Make precise overall adjustments or correct targeted areas.

Highlight and Shadow Recovery
Bring out all the detail that your camera captures in dark shadows and bright highlights. Now you have more power than ever before to make great images under challenging lighting conditions.

Selective Editing Brushes
Extend your creative control with a flexible brush that lets you adjust selected areas of your photo for just the look you want.

Extended Video Support
Organize, view, and make adjustments and edits to video clips. Play and trim clips, extract still images from them, or adjust clips with the Quick Develop tool.

Advanced Black-and-White Conversion
Gain powerful control over tonal qualities that can make or break black-and-white images. Precisely mix information from eight color channels when you convert to grayscale.

Fast Performance Across Platforms
Speed up day-to-day imaging tasks and process images faster with cross-platform 64-bit support for the latest Mac OS and Microsoft Windows operating systems.

Photo Book Creation
Create beautiful photo books from your images with a variety of easy-to-use templates included in Lightroom 4, and then upload your book for printing with just a few clicks.

This version is an upgrade only,and requires a previously installed, active version of Lightroom 1, 2 or 3 to complete the installation.

Specifications:

Windows
Intel Pentium 4 or AMD Athlon 64 processor
Microsoft Windows Vista with Service Pack 2 or Windows 7 with Service Pack 1
2GB of RAM
1GB of available hard-disk space
1024x768 display
DVD-ROM drive
Internet connection required for Internet-based services

Mac OS
Multicore Intel processor with 64-bit support 
Mac OS X v10.6.8 or v10.7
2GB of RAM
1GB of available hard-disk space
1024x768 display
DVD-ROM drive
Internet connection required for Internet-based services

Individual license covers up to two separate computers