One of the new features of LR3 is the lens correction piece in the Development Module. While there are a number of ways to use it, I only ever click the “Enable Profile Correction” option and trust in it. Using the EXIF data, LR3 knows what lens you’re using and automatically corrections for natural vignetting and distortion for you. You can still tweak it, but why bother? It’s a lot of work.
The correction doesn’t do much with a standard lens, but with my widest lens, a Tamron 17-35mm job, it works wonders.
In fact, it saved a time lapse I set up the other day. Here’s a before picture:
I set my camera up just inside my garage and pointed it out over an open area of sky across the street. I kept the camera low to the ground, tried to go all the way to 17mm with the lens, and shot at F/11.
There was something I didn’t notice until I got back to the computer, though, and that’s the black mark in the upper left corner of the image. That’s the garage door frame. It shows up just inside the frame that I had composed and it annoyed me. It’s not a big thing. It doesn’t hide the clouds anymore than a heavy vignette would. Lots of people would likely never notice it. But it bugged me. I’m better than that.
The first edit I made was to click on “Lens Correction” before applying some other settings I did in previous pictures. Look at where that sliver of garage door is now!
Gone! How? Because lens correction isn’t magic. It loses pixels when it straightens things up. Yes, it also brightens things up along the edges to account for lens correction, but it also need to lose pixels at the age to allow for the picture be to whole. That pushes things along the edge of the frame in this particular car. You can see that the garage door is close to the edge originally at the cornerly, and so falls easily.
So what have we learned today? Lens Corrections works with wider angle lenses by pushing pixels off the edges to make the new construction. It eliminates some vignetting, most likely by applying negative light.
Also: Look carefully at how much work your circular polarizer is dialed in. The sky seen in this picture was never THAT blue. UGH.