The Artful Engineer

In early October—before our visit to Michigan—we spent a weekend in Leadville, Colorado. Family events collided with our getaway, so we ended up spending one day driving north to Wyoming and back. It was dark on the return trip, but on the way up we got to enjoy driving through valleys sporting some fall color. The clump of trees is a nice focal point in the image above: it stands out against the successive layers in the composition. The dark shadow also makes it the highest-contrast spot in the image, by far, which garners it attention as well.

Northern Colorado starts to reach into sagebrush country. Those dry, wide open spaces make for quite the contrast with the aspens on the slopes above:

There were some areas, too, where the fall colors were surrounded by sagebrush:

For this next image, I wanted to give a brief overview of how I corrected a common problem with blue skies. If you are a photographer that processes your images, this might be of interest; if not, I won’t be offended if you skip ahead a bit.

This next figure shows the “before-processing” sky above the “after-processing” sky. If you look at the former, you can see that the sky on the right side of the image is darker than the left side of the image. This commonly happens with polarizers when the sun is out of the frame off to one side (in this case the left) but sometimes it happens even without a polarizer. Wide angles make this even more of a problem, to the point where some people will advise never using a polarizer with a wide angle. This image is actually a telephoto image at 115mm, but it still shows the problem. Regardless, despite assertions to the contrary, it isn’t terribly hard to correct, and I’ll briefly explain how I did so in Lightroom.

In Lightroom’s Masking module, I first made a sky mask. Then, I intersected this with a linear gradient across the width of the image from right to left. (If you hold down the option key on a Mac—which should be the alt key on Windows—the Add and Subtract buttons change to a big Intersect button. Why it is hidden this way only Adobe knows.) If you look at the little thumbnail next to “Mask 2” you can see that the area corresponding to the sky is white on the right and fades to black on the left. This means that any adjustment I make using this mask would affect the right side of the sky but not the left, with the center area somewhere in the middle. All I did was add about half a stop of exposure and that was enough to balance out the exposure of the sky left to right.

So how do you know how much exposure to add? You can eyeball it, but a less arbitrary way is to use the histogram. This next histogram is of the image before the sky was adjusted: notice how the blue hump on the right is pretty spread out. (It actually looks like a couple of peaks right next to each other more than a single hump.)

After the adjustment, notice how the blue hump on the right has turned into a sharp peak. The fact that it is all packed tightly together is indicative of the sky being (mostly) one tone. So, you can just move the exposure slider for the mask and watch it sharpen up; when you have gone to far, it starts to spread out again. Just find the sweet spot.

Note that I didn’t correct the vignetting, so the two corners are still a little darker than the center, but the key thing here is that the right side isn’t a lot darker than the left. I actually did the same trick with the earlier image (Aspen and Sage) that shows the sky, but with the added step of removing the clouds from the mask.

We’ll finish up with a classic vertical S-curve composition: rather than a river, though, we have bright gold aspens weaving their way between sage-covered hills. There’s just a touch of mystery to the image, too, where the trees disappear around the bend. Expanses of sagebrush is pretty in its own way, but its main compositional function in all of these images is as fairly neutral backdrop against which other things can be featured.

I hope you have enjoyed these images—and maybe learned an editing trick to try, too. Next week I have some more fall color to share from around Leadville itself.