View Full Version : Straightening the horizon in Photoshop

Richard Hall
31-05-2020, 12:21am
I made comment in a recent thread about horizons that are not straight in bird photos. It's one of the very first things I'll notice, and it's particularly noticeable in images of birds on the water. It gives the appearance that the water's going to run out of the frame and doesn't look right or natural. The only reason you'd want to keep it crooked is if you were trying something a little more arty in style where it's needed.

Obviously it's ideal to get it right in camera first rather than correct it later but sometimes it just happens! If you have the ability to turn on a horizon level in your viewfinder or a rule of thirds grid lines overlay I'd recommend this as it'll help judge the level before you press the shutter.

The steps I use in Photoshop are as follows:

Step1: With this image loaded in Photoshop you can see how the bird is leaning heavily to the left (I rotated this to exaggerate the effect).

Step2: Right click the Eye Dropper tool and select the Ruler Tool.

Step3: Using ripples (or sometimes the underside of the bird if it's parallel to the camera) can be the easiest way to check the rotation amount needed. With the ruler selected from the previous step, left click on a central point of a ripple and hold the mouse button down then drag the line out to the centre of ripple on the other side of the bird, then release the left mouse button. A line will be drawn corresponding to how the horizon will be straightened.

Step4: Go to the Image menu and chose Image Rotation, then Arbitrary.

Step5: After choosing the Arbitrary method a window pops up with an angle that it's measured and a rotation direction. Click OK and the image will rotate along the line we've drawn, straightening the image.

Step6: You can see the image has rotated along the line, the downside is you will lose canvas around the edges due to the rotation. This is one reason why it's important to get the level right in camera in the first place! If your subject fills the frame you may have some of the subject cropped out of frame or it gets pushed to close to an edge to compose the image properly.

Step7: Now crop the image again as you normally would paying attention not to keep in any of the black areas where the image has rotated and you've lost actual canvas of the photo. If you do keep in some of the black cropped areas you may be able to clone in some background to replace it if it's a plain simple background, honestly though it's generally not worth it... get it right in camera first!

Step8: et voila! You now have a perfectly level horizon with no water running out of the frame! :lol:

The same results can be performed in Lightroom with a similar technique, if there's any interest I can do a quick tute on that too.

31-05-2020, 12:47am
Nice. That was awesome. Of all that though - I love the tip on using the extreme points on the ripple, that's smart! Will definitely remember that one.

I Like to Watch
31-05-2020, 11:03am
The steps I use in Photoshop are as follows:

Interesting method.

Any reason you choose this way over the Filter -> Lens Correction -> 'Spirit Level Tool' ?

31-05-2020, 2:51pm
Clicking the crop tool brings up a straighten tool?

Richard Hall
31-05-2020, 3:53pm
Any reason you choose this way over the Filter -> Lens Correction -> 'Spirit Level Tool' ?

Clicking the crop tool brings up a straighten tool?

Like a great many things in Photoshop there's more than one way to accomplish the same task. They all do exactly the same thing though, draw a line along the path that needs straightening. I favour this method (although the crop tool/straighten is much the same) purely because I like to straighten the image then crop once it's rotated, the crop/straighten tool leaves the image on an angle as you crop and I find it harder to judge a crop precisely when the image is crooked. It's just a minor difference. I should add, I've been using this method long before PS had a straighten tool in it. ;)

Whichever method you choose, the main point of my post was to highlight the importance of checking your horizons are level, I see photo after photo with crooked horizons and all it takes is a 5 second fix to resolve the issue!