The Bell Tower Problem

I shoot of a lot of Architectural photographs of churches that have a bell tower. A particular problem arises when I want to make a two point perspective shot of the building, with a wide angle shift lens with an angle of view greater than 28mm. (It is not always possible to back off and shoot with a longer lens.)

The main building looks fine, but the bell tower often has a strange perspective, due to the two point perspective lines laying on different planes. Here, below is a shot of the Pieve in Vigoleno, shot with just vertical perspective correction.

The bell tower looks strange. This is not distortion. The picture obeys all the rules of two point perspective.

A method I use, and which you will not find in many texts that explain the use of shift lenses, is to use diagonal shift. In the case of this church, the sensor plane should be parallel with the façade and bell tower front. Then using diagonal shift the church is framed to our liking.

The result is the shot below, taken from the same position.

The result is a much more natural looking picture.

I returned sometime later to make a more dramatic blue hour shot.

When the bell tower is on the front face, diagonal shift is not generally needed. This is St Clement's Church, Old Romney

This exaggerated two point perspective example shows that the two point perspective vanishing lines are coplanar. This is why the bell tower does not seem distorted. Chiesa di Sant'Ambrogio,Uscio, near Genoa.

Sometimes, diagonal shift, is useful to reduce the two point perspective effect when you cannot take a one point perspective view for reasons of space. S. Giorgio, Parma

The shots above were made with a shift lens. The same corrections can be made with post processing software, at the cost of losing large areas of the picture. This is a corrected shot made from the first picture in this post. 

There is another problem with old churches with bell towers. The church below was built almost a thousand years ago, on the side of a mountain. It has weathered a few earthquakes as well. The foundations are probably almost non existent. In time the bell tower had moved out of plumb. The church itself has walls that lean. 

There is no optical way of  correcting all the effects of time, that this building has suffered. I just have to live with the strange distorted look of the church, particularly, the bell tower in this shot.

S Paolo Vendaso, Fivizzano