Slated for introduction in Photoshop Lightroom 3, as well as in Adobe Camera Raw 6.1 (which will be soon follow as a replacement for Camera Raw 6.0, which ships as part of Photoshop CS5), the lens correction functionality looks impressive, to say the least. Geometric distortion, chromatic aberration and lens vignetting can all be corrected automatically using lens profiles. The same changes can also be made manually, and it will also be possible for users to make their own lens profiles using a freely available tool.
Interestingly, the lens correction function is capable of dealing with more than just straightforward barrel or pincushion distortion -- it can also fix wave distortion, where some areas of the image exhibit barrel defects, and others have pincushion defects. There are also adjustments for horizontal and vertical transformations, helping to deal with subjects that couldn't be shot straight-on.
Where it really gets cool, though, is that individual defect types can be adjusted separately. For example, one might have an image where the chromatic aberration was objectionable, but the vignetting was desirable, and some degree of distortion might also add to the aesthetic. (Just such an image is shown in the preview window). This can be taken into account by simply automatically correcting the image, then adjusting three sliders that alter the strength of each effect -- distortion, aberration and vignetting correction -- individually.
To see the video, hop on over to Adobe's Lightroom Journal blog.