One of my favorite features within Lightroom is the Straightening Tool. I have the exceptional ability to consistently produce images with slightly crooked horizons; my theory is that I am somehow 5 degrees off kilter to the planet. The Straightening Tool fixes this quickly and easily; click, drag, fixed! But, you don’t always have a distinct horizon to go by to get things straightened out, which requires you to do some experimentation to get your shot looking right.
Since I photograph around a lot of water, I picked up a trick in Lightroom I call “reflection correction”. A reflection from a relatively flat surface will always appear perfectly parallel to the object it is a reflection of. Any photo that with a reflection in it is easily straightened just by aligning your subject to its reflection.
Straightening Your Shots
To level your shot, select your Crop Tool in the Lightroom Develop Mode, then select the Straightening Tool (you can do the same in Photoshop using the Ruler Tool). Pick something that is distinctly clear in the reflection. Usually I pick the eye if it is an animal, or a distinct feature like a tree if it’s a landscape. Click once on the feature you picked, then click the same point in its reflection, and you will see your image instantly straightened, according to the laws of physics.
This will work for any type of reflection, horizontal or vertical, in any flat(ish) material (water, glass, metal, etc.). However, I make no guarantees when it comes to fun-house mirrors. Also remember that sometimes our eyes deceive us. You may encounter an optical illusion, like a curved shoreline, which makes a level scene look crooked. In these instances, use your best judgment for what looks right… or tilt your monitor. Photo: Sunrise over the Ochlocknee River, Florida. Gear: Tamron SP 150-600mm F/5-6.3 Di VC USD A011 / Canon EOS 5D Mark III
Why Does this Work?
For those of us who like to know “how stuff works”, this is thanks to the nature of light and a handy bit of physics called the “law of reflection”, which explains how mirror images occur. When light encounters any material, three things can happen: the light either passes through, gets absorbed, or bounces off (reflection). The amount of each depends on the properties of the material, the wavelengths of the light, and the angle the light hits at, known as the angle of incidence. The law of reflection states that, “when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.” In the case of water, think of it like laying a mirror on the floor. When light hits it, some is absorbed, and some passes through. But a lot is reflected, bouncing off at the same angle it hit at (angle of incidence), creating a mirror like effect. Your subject’s reflection will be the same size, reversed, and directly below it. If your subject and its reflection don’t line up when you review your images, grab that straightener and fix it in two clicks!
Keep in mind, if using a lens that has barrel or pin-cushion distortion (an issue in some lenses, especially wide-angle ones), you will need to correct that in addition to leveling the image. Check out my article “How to Make Distortion Disappear with Lightroom’s Transform Tools” for a fast and easy method to fix this problem!