All in all it is pretty easy: Lightroom provides a simple tool to correct chromatic aberrations. Since Lightroom 3, you don’t eve have to do this yourself, when your lenses are registered in the lens correction profile database
So let’s begin:
1) Select the file you want to process, if you want to make a HDR, select the first shot of your series:
2) This does not look good: Heavy CAs on the left boarder. Go to the lens corrections the toolbar:
3a) Now there are two possibilities to remove them: manually or via the lens correction database. First, let’s do it the hard way
Move the "Reset Chromatic Aberration" sliders to a position where the CAs disappear from your shot. This is a fun work, since the CAs may not be identical on different focal lengths or apertures.
3b) If you’re lucky (and own Lightroom 3), you can also use the profiles supplied with LR.
4) LR can also correct lens distortions and vignetting, which is pretty neat. Looks much nicer now, right?
5) Bracketed images can be corrected in a batch via "Sync settings". Mark all shots of the series and select the first one. Then open the context menu as shown here:
#7 Finally you can export the images for further processing in Photomatix Pro. If you use a HDR engine not supported in lightroom, use the TIFF export.
I hope this small howto helps a bit. If you have any questions or suggestions,give me a shout in this thread