Happy holidays everyone! Good to be back posting at Lightroom Secrets.
One of my favorite features in Lightroom 3 is the ability to straighten out architectural images with help from the new Lens Corrections panel. While it's no substitute for a real perspective correction lens, it can go a long way towards improving distorted images. There are two modes available with this panel: profiled corrections and manual corrections. The former use special lens profiles that define the types of distortions that occur with a particular lens, at a particular focal length and distance. Profile corrections are an automated process within Lightroom 3. That is, if a profile for your specific lens exists in the database used by Lightroom (and ACR and Photoshop), it is automatically detected via the file's EXIF info and a correction applied. This can save a lot of time when you have a simple barrel distortion issue or other minor flaw.
However when you have multiple elements in your composition that introduce skewed perspective lines, the Manual mode can be the best way to go. The controls are similar to the traditional Lens Correction Filter controls in earlier versions of Photoshop, so if you know how to use those, you're already ahead of the curve! The video below details the process for making Manual Lens Corrections in Lightroom 3.
You can check out more free Photoshop and Lightroom tutorials, as well as interviews and product reviews by Dan at Colortrails.com.