How to correct shifting lines in photographs

If you take photographs, you’ve probably encountered this situation: You’re trying to photograph a building or a group of buildings, but you can’t move back any further. So in order to get the whole structure into the picture, you use a wide angle. In the resulting frame, the houses look like they’re about to fall over. This phenomenon is caused by a distortion of perspective brought about by the wide angle lens, the so-called shifting or converging lines. In many cases, a free software called ShiftN can help. It automatically corrects shifting vertical lines and turns them into straight verticals.

The video below shows you what this software can do.

This is how the programmers describe this free software: “ShiftN permits correction of converging lines; a majority of the correction work is taken over automatically by the program. Using the ‘automatic correction’ item in the menu is in most cases sufficient to produce a satisfying result. Both the effects of converging lines and poor camera angle are corrected automatically.”

It works, but it doesn’t work wonders

If you use ShiftN to correct converging lines, be careful not to overdo it. Seeing only straight verticals instead of shifting lines doesn’t look natural. Your photos will seem awkward and unnatural.

ShiftN is great if the distortion is only minor, as seen in the example video. But a case like those white high rises you see at the top of this page is too much for ShiftN’s automatic correction.

As you see on the right, the way ShiftN “corrected” this picture looks artificial. The manipulation is obvious and makes the viewer uncomfortable.

In some cases, you’ve just got to take another step back to get the perfect picture – or be prepared to live with converging lines.

By Thorsten Karg