Photoshop – Tilt & Shift Correction
We have all taken images when we are restricted in the position of our vantage point, so we have to tilt the camera upwards and shift the camera sideways to get the image in the frame. The result of tilting and shifting the camera is that the verticals and horizontals of the image are converging.
The original below shows the converging verticals and horizontals of an image of a mural in Iglesia de Nuestra Señora de la Asunciónin in San Sebastian de La Gomera. Due to the location of the mural, I did not have the option to get in the right position to avoid even part of the effect.
The best way to correct for converging verticals is to use a camera or lens that enables tilt and shift movement of the lens, such as the Canon TSE lenses. Unfortunately, I do not have one of these specialist, extremely expensive tilt and shift lenses, so this option is not available to me.
An easy alternative is to correct tilt and shift in Adobe Photoshop using the ‘skew’ functionality. The process is very simple: select the whole image, select the skew tool found in the edit menu, drag appropriate corners to skew (or more correctly un-skew) the image, and crop or trim the image appropriately.
This is simple and very effective, as the final result below shows, but the quality of the resulting image cannot compete with that achieved using a tilt and shift lens. To achieve the best result with this edit, skew the corners in rather than skew the corners out, as the latter would result in image degradation due to interpolation.