Perspective correction

We have all taken images of buildings when we have to tilt the camera upwards to get the whole building in the frame. The result of tilting the camera upwards is that the perspective of the building is skewed with the verticals converging. The original below shows the converging verticals of an image of a ruined building in Agulo on La Gomera. Normally, I would take quite a few steps backwards to to minimise the converging of verticals, but as this house was in a narrow cobbled lane, I did not have this option.
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 the converging verticals in Adobe Photoshop using the ‘perspective’ functionality. The process is very simple: select the whole image, select the perspective tool found in the edit menu, drag a corner to skew (or more correctly un-skew) the image, and crop or trim the image appropriately, as illustrated below (click on a thumbnail to enlarge a screen grab). If there is one bit of functionality I would like Adobe to include in the next version of Lightroom then, without a shadow of a doubt, this would be perspective correction.

This is simple and very effective, 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 bottom in rather than skew the top out, as the latter would result in image degradation due to interpolation.

The original and final image below show how this quick and simple edit can give you the result you desire.

Away with the crane

The big crane spoiling this spectecular sunset over San Sebastian de La Gomera has been an eyesore for years and can be seen in, unfortunately, too many of my images of the town, including the virtual reality taken from the terrace at Casa Cathaysa. Looking at the image below, you may think that the crane is not that bad, but trust me, on a large screen or on an enlargement print, it is very obtrusive.

This image is created from eight seperate 21mp images, that I stitched together into a panorama using Photoshop. The panorama measures a massive 11,200 by 5,300 pixels and would have required a ‘not yet existing’ 100mp digital camera to be taken in one single image, taking into account the need to crop the normal image format to a letterbox format. Without compromising the quality of the print, by printing at 300dpi, it can be enlarged up to 95 x 45 cm (or 37.3″ x 17.6″). Therefore, this image is a prime candidate for an enlargement print if it was not for that bloody crane.

So this image needs a little bit of Photoshop magic to get rid of that crane.

The two images above show a detailed closeup of the houses on the hillside with the crane partly obscuring them, and after removing the crane using the clone stamp tool in Photoshop. Due to the detail in the houses on the hillside, removing the crane was a slow and laborious task that took some time. But, as you can see from the detail above and the final image below, it was well worth it.

Colourful Corsica

The Great Mosque in Aswan