Straighten those Horizons

© 2009 Simon Hucko

The thing about spending a week on a giant boat is that you wind up with a lot of photos of the water. The thing about water is that it makes a straight horizon. The thing about straight horizons is that if you screw it up and the horizon comes out even a little crooked (we're talking fractions of a degree) people immediately notice and are bothered by it.

I knew this going into the trip, so I took extra care to make sure my horizons were straight. However, even if it looks right through the viewfinder, you may still find that your images came out a little crooked (sometimes just the action of pressing the shutter is enough to knock things off-kilter). The solution is to double-check everything when you're editing and make sure you straighten your photos. Different editing software has different ways of straightening photos. Aperture pops up a grid overlay when you're adjusting it, so it gives you a nice reference for the horizon (or other straight horizontal or vertical lines). I believe the new versions of Photoshop have a feature where you draw a line along the horizon and it automatically straightens the image. However you do it, make sure to get it right or everyone will start feeling sea sick after flipping through your vacation photos.

As an example, here's the above shot rotated by 1 degree:


Makes a huge difference, no?

(As a side-note, you can see the barrel-distortion from my lens in both of these shots. Most zooms have some amount of barrel distortion at the wide end and pincushion at the tele end, which is another advantage to prime lenses. This distortion can be removed using various software, but I don't have any in my possession at the moment.)

A few tips to avoid crooked horizons:
- Use a tripod to level and steady your camera
- Turn on the grid display in your viewfinder
- Get a level for your hotshoe, something like this
- Double check and straighten your photos if necessary in post

~S

[title of blog] on flickr