Correcting vertical perspective

When out shooting in cities, most photographers will take pictures of architecture, grand old buildings, historical monuments, and even new developments that might be architecturally fascinating. Architecture makes a great subject, but unfortunately, because most of us photograph from the ground level (and therefore have to point the camera upward), our pictures might suffer from extreme optical distortion.

Unfortunately, this is part and parcel of the photography technology available to us. By packing more information into a small frame using a wide-angle lens, the optical system cannot help but distort some of the vertical and horizontal lines. Shooting horizontally, from an upper floor opposite a tall building, means that you're likely to suffer less optical distortion because there's less reason to tilt the camera up to get everything into the frame. The following image shows one way around the problem of extreme optical distortion:

In the days...