Perspective corrections
In the Manual tab section of the Lens Corrections panel, we have the Transform controls. The Distortion slider can be used to apply geometric distortions independent of the Distortion slider in the Profile tab section. The Vertical slider can be used to apply a keystone correction to the converging verticals in a photograph, such as when the camera has been pointed up to photograph a tall building. The Horizontal slider can similarly be used to correct for horizontal shifts in perspective, such as when a photo has been captured from a viewpoint that is not completely “front on” to a subject. The Rotate slider allows you to adjust the rotation of the transform adjustment (which is not the same as rotating the image). While it is possible to use the Rotate slider here to straighten a photo, you should mainly use the straighten tool in the Crop Overlay mode (R) to do this. However, in the example, I did end up using a combination of a Crop Overlay rotate (which isn’t included as a step here) and Lens Corrections panel Rotate adjustment to achieve the ideal combined rotation. Finally, the Scale slider allows you to adjust the image scale so that you can zoom in or out. As you reduce the Scale amount, the outer image area will appear as an undefined gray padded area (see Step 3). Although Lightroom does not offer any options for filling in this border (as you have with the Lens Corrections filter in Photoshop), there are still ways you can do this in Photoshop itself when retouching a rendered pixel image that’s been exported from Lightroom.
Figure 6.58 The Lens Corrections panel showing the Manual tab options, with Transform adjustments applied to an image.
- In this initial step, you can see an example of a photograph that was shot using a 15 mm fish-eye lens, where there is a noticeable curvature in the image.
- In the Lens Corrections panel, I simply checked the Enable Profile Corrections box to apply an auto lens correction to the photograph. In this instance, I left all three Amount sliders at their default 100 percent settings. If I wanted to, I could adjust these sliders to apply more, less, or no adjustment. For example, I could have chosen to apply a 50 percent Amount Distortion correction with a 0 percent Vignetting correction.
- Next, I clicked the Manual tab in the Lens Corrections panel so that I could adjust the Vertical transform slider to correct for some of the keystone distortion in this photo. I also adjusted the Horizontal slider to center the two overhead poles. Finally, I rotated the transform adjustment –3 clockwise and adjusted the Scale slider in order to zoom out slightly and reveal more of the image content.
- Finally, I opened the photo in Photoshop CS5 and used the new Content-Aware Fill feature to fill in the gray space at the bottom. If you are interested in seeing how this was done, I suggest watching the movie that’s on the book’s Web site.