The horizon line is a big deal in landscape and other outdoor photography. You can’t do this kind of photography for long without encountering the Rule of Thirds and the Golden Ratio, both of which are usually applied to the horizon line. Even if there isn’t a true horizon line in your picture, there’s often a line running through the picture that determines whether it will appear level.
Still, it’s surprising how often people end up with crooked lines. You might not notice it, but it’s often the first thing people will see when looking at your photo. Posting a good photo only for it to appear crooked can be embarrassing. Beginners are notorious for overlooking this, but it happens all the time. It even happens to me occasionally.
In this article I’ll walk you through ways to make sure that your horizon line is straight.
But before we get into that, start making sure you actually check it. After all, it’s an easy thing to forget. Do whatever works for you, whether it’s making a checklist, leaving yourself a note or whatever. And make it a part of your workflow so you do it every time.
Sometimes it can be hard to tell whether your horizon line is straight or not, even when using the level in your camera. It gets especially hard when it’s mixed up with other elements in your picture that aren’t straight either. Add in lens distortion, and you can end up with a convoluted mess.
So let’s talk about tools and techniques for keeping your horizon line level. We’ll go from the most obvious tools that you probably already know about (but worth a little refresher) to some less obvious tools and techniques.
1. Use the Crop Tool Effectively
The easiest way to straighten your horizon line is with the crop tool. Virtually every photo editing software package in existence has a crop tool, so it should be familiar to you.
Most of the time this tool will also let you change the angle of the picture. And quite often that’s all you need to do.
In Lightroom or Adobe Camera Raw (ACR), select the Crop Tool and then move your cursor slightly off the picture. The cursor will change to a curved line with arrows at either end, which indicates that clicking and dragging will now change the angle of the picture. Click and move it around to straighten your horizon line.
You can also do it by filling in the angle percentage on the far right.
2. Avoid Distortion
Sometimes your picture will appear crooked even when it’s level. That’s because most lenses have at least some barrel distortion, which makes the horizon line sag toward the sides of the picture.
This really affects things when you crop one side of your picture. The sag will show on one side (the one you didn’t crop) but not the other, and so your picture will appear to be leaning to one side.
You can fix this with the leveling functions mentioned already. But another way to fix it is to cure the distortion, which can be done easily in Lightroom and ACR.
Find the box labeled Lens Corrections, and check the box next to Enable Profile Corrections. The software will then apply an automatic correction tailored to the lens you used. You might need to help the software find your lens by selecting the manufacturer and perhaps even the model. But usually the software will find it for you and apply an automatic correction.
3. Transform to Correct
Sometimes you need a little help determining what is truly level. Your eyes can play tricks on you, particularly when you have different lines running in different directions in your picture. Lightroom can provide some help in the Transform panel.
The best way to get familiar with these controls is to just play with them. Go through them all and watch how they affect your photos. After that, you’ll know which controls will be the most useful.
You can have Lightroom level your photo automatically by pressing the Level button at the top left. However, this doesn’t always work, in which case you can do it manually using the Rotate slider.
This is a great set of tools to use when you have multiple distortions working at the same time. Here’s a picture that isn’t level, and also seems to be suffering from vertical distortion.
And here’s the same picture after pressing the Auto button in the Transform panel.
Pretty dramatic improvement, isn’t it? If you don’t like what you get, you can always perform manually tweaks using the sliders. It won’t always be that easy, but sometimes this control is like magic.
4. Use the Ruler to Test
Okay, so how can you tell if your horizon line is actually level? We already talked about the Level command in Lightroom’s Transform panel. But there’s perhaps an even better way – Photoshop’s Ruler tool. It isn’t intuitive, and isn’t something you’d know about until someone shows you.
Start by selecting the Ruler tool from the tools on the left side of your screen. Then draw a line along your horizon line. If you can’t see all of the horizon in the picture, just use the part you can see. And don’t worry – you can re-do this as many times as you want.
Once you’ve drawn your line:
- From the main menu choose Image > Image Rotation > Arbitrary. This will bring up a dialog box with a number in the angle box. This is the angle Photoshop has set based on the line you just drew with your Ruler. Don’t change it.
- Click OK.
Photoshop will now level the picture according to the line you just drew.
If it looks right, crop away to fix the edges. If it doesn’t look right, just undo it and try again.
5. Add Distortion to Correct Without Cropping
Here’s another Photoshop technique to level the horizon line doesn’t involve any cropping at all. You simply distort the image to pull up the low end of the horizon line.
Start by selecting the entire image. You can use whatever selection tool you’re most comfortable with, or just press Ctrl+A to select the entire image. Once you’ve selected it, choose Image > Transform > Distort from the main menu.
Your image will now have a series of little boxes on the edges and corners. By dragging these boxes around you can distort the image. You might want to play with them a little to get comfortable with the tool, as it can be handy in a variety of contexts.
For our purposes. just pull up the corner of the image on whatever side the horizon line is low until it’s level. Your picture is now level without needing to be cropped.
You can combine this technique with any other distortions you might want to fix, such as correcting converging buildings.
Putting it in Practice
Just thinking about having a straight horizon line goes a long way. Correct any other distortions first to get a sense of how the picture will ultimately look.
If you’re having trouble determining whether your horizon line is level, you can check with either the Level command (Lightroom and ACR) or the Ruler combined with the Image Rotation command (Photoshop). Use both to get a sense of what feels right.
But ultimately there’s no mathematical way to do this. It’s what you see with your own eye that’s most important.