Straighten Buildings With The Lens Correction Filter

It’s new to CS2: the Lens Correction filter, which allows you to straighten buildings and fix perspective within an easy-to-use interface.

Some time ago I wrote an article on straightening buildings with the Crop tool, and I’m following up with this How-To on doing the same thing with the Lens Correction filter (it’s in the Filter –> Distort menu). Lens Correction is new to CS2 and it’s a robust interface for fixing various distortions and color changes created by the use of a camera lens.

Figure 1: Salisbury House.

Figure 1 above is the Salisbury House, which we used in my earlier tutorial.

Step 1: Select Filter –> Distort –> Lens Correction…. The Lens Correction dialog box appears (Figure 2).

Figure 2: The Lens Correction dialog box. Click the image to see a detailed view.

The Lens Correction filter has a lot of options, including fixing chromatic abberation, curvature distortion and vignettes (it’s also great for creating vignettes as well). But for our purposes we just need to fix the vertical perspective just a bit and so the only slider we really need to worry about is the Vertical Perspective slider in the Transform area of the dialog box.

Step 2: Drag the Vertical Perspective slider until both sides of the building are perpendicular to the horizon line (see Figure 3). Note that if your image was shot at an angle, it will be impossible to get both sides perpendicular unless you tweak the Angle setting directly below Horizontal Perspective.

Figure 3: After Lens Correction..

Step 3: Click OK to save your changes to the image and crop and sharpen as necessary. I find that Lens Correction blurs the edges a bit, so sharpening helps.