The headline feature of Lightroom 2 will be localized corrections. Sure, multiple monitor support is nice, print packages are pretty cool, and 64-bit support are all great additions, but localized corrections are what really will get people's excitement going. Because of the non-destructive nature of Lightroom, however, the way that localized corrections are implemented might take a bit of time to get used to. When you first start using the localized correction tools, it's really easy to think that you're painting in exposure or saturation onto the image as that's what it feels like, at least at first. When I started using them myself, I found that the mental model of painting in a correction fell apart very quickly. For example, when painting in exposure, the areas I was adjusting only increased in value just so far and then stopped.

It seems rather silly now, but there for a few moments, I was wondering what the heck was going on. And then, I looked over at the sidebar and made the connection between the slider and the region that I had just painted. "Ah ha! I'm not painting a correction," I said to myself, "I'm painting a mask!"

And just like that, a mental model that worked popped into place and away I went making localized corrections all over the place. Furthermore, it made perfect sense when I found that it was possible to adjust more than one parameter, such as increasing contrast while reducing exposure, for a mask. If I had been thinking about brushes as "exposure brushes", this wouldn't have worked very well.

Of course, it'd have helped if I had actually noticed that the localized correction interface very clearly uses the word mask. But, I'm not sure that would have stopped it taking any less time to really sort out what was going on with these tools. Sometimes, the best way to get a handle on what's going on is to just play with the knobs until you see how everything is related.