Today’s Question: For photos where you do want to have the lines appear perfectly horizontal or vertical, how do you recommend achieving that result?
Tim’s Quick Answer: To achieve perfect alignment in an image, I recommend applying profile-based lens corrections as well leveraging the Guided option for the Upright controls. Both of these adjustments (and additional manual controls for fine-tuning) can be found in both Camera Raw and Lightroom Classic.
More Detail: Today’s question is a follow-up to an answer I shared last week, where I explained that it wasn’t always necessary to have lines in an image appear perfectly horizontal or vertical just because that seems like the right approach. However, when you do want to achieve this type of alignment, a couple of adjustments can prove tremendously helpful.
As a basic starting point for achieving good alignment for a photo I recommend enabling the profile-based corrections, which apply a correction based on the behavior of the specific lens used to capture the image. Just keep in mind that not all lenses are supported for this feature.
To apply profile-based lens corrections turn on the “Use profile corrections” checkbox on the Profile tab of the Optics section of the right panel in Camera Raw, or turn on the “Enable Profile Corrections” checkbox on the Profile tab of the Lens Corrections section of the right panel in the Develop module in Lightroom Classic. Then make sure the appropriate profile is selected from the Profile popup based on the lens used to capture the photo.
I then recommend using the Guided option for the Upright corrections found in the Geometry section in Camera Raw or the Transform section in Lightroom Classic. With the Guided option you can draw between two and four lines to define lines in the image that should be perfectly horizontal or vertical. For example, with a photo of a building you might draw a line across the top of the roof and along the foundation line at the bottom, and then along the left and right edges of the building. This will apply a correction so the lines you drew are perfectly horizontal or vertical, which in turn means perspective of the image will be corrected accordingly.
You can also use the sliders in the Geometry section of Camera Raw or the Transform section of Lightroom Classic to further refine the overall perspective correction for the image, such as to further ensure that lines within the image appear perfectly horizontal or vertical.