1/125″ /F7.1 / iso100 / 18mm
Lovely architecture, but why is it falling over?
There’s a problem you will often see when you’re shooting buildings or bridges. Everything looks fine through the viewfinder and in person, but after you take the shot, you’ll notice that the building looks like it’s tipping over. This is known as the Keystone Effect. No, this has nothing to do with the controversial pipeline that might run through Canada.
If you know anything about human vision, you’ll know that while the eye takes in the image, the brain is the organ interpreting it. When we stare upwards at a building, we usually won’t notice any strangeness because our brain reinterprets the building as vertical. There’s a “brain” inside our cameras (the microprocessor), but it isn’t as clever as the brain above our shoulders.
Therefore, we get this keystone effect where vertical structures appear tipped over. Sometimes it looks fine, but usually you’ll want to fix it. There are two ways to do this, the expensive way and the non-expensive way. As is often the case, the expensive way yields the best quality. You’ll need to buy a special tilt-shift lens for thousands of dollars and then you’ll be able to shoot architecture and adjust the lens to combat keystoning.
Most people don’t have those lenses, and don’t want to spend so much on a special lens like this. I am one of those people.
We can fix this issue in Lightroom. Here are some caveats. #1. You will need to crop the shot somewhat. Keep this in mind when shooting. #2. Oftentimes the top bits of the buildings (or in this case the bridge), won’t be as sharp. It helps to use a narrow aperture to make sure you have enough detail at the tops of the structure.
Use the straighten tool to straighten the image as much as possible. A quick way to get into this mode is to press “R” on your keyboard. This will bring you to the crop layout. Next, hold the CMD key (Mac) or CTRL key (Windows). Drag a line either vertically or horizontally along the picture where you think it’s supposed to be perfectly vertical or horizontal.
Now it’s time to fix the keystone distortion. In Develop Mode, scroll down on the rightmost panel until you see Lens Corrections. Check all three boxes, Enable Profile Corrections, Remove Chromatic Abberations, and Constrain to warp.
Below this, you will see the Upright tools. These are automatic tools where Lightroom analyzes the shot and tries to fix the image automatically for you. Sometimes it works, sometimes not. Click each one and see which one helps the most. If that doesn’t do the trick, you’ll need to play around in Manual mode in Lens Corrections. I usually start with horizontal correction, then move to vertical, then distortion. You might want to experiment and move the sliders one at a time all the way to the right or left in order to figure out exactly what effect they have on your image.
You’ll just have to play with these sliders until the structure looks correct to you. You also might need to adjust the crop again. Use the “R” key to get back into crop mode.