34 CONTEXT 182 : DECEMBER 2024 If you stand directly in front of a building and look to the left, the lines point to the horizon. But worryingly, look to the right, and the lines point to the opposite horizon. How can this be? Is the building bent in the middle? I have a suspicion that our eyes practice a deception on us. To get all of a building into a photograph, it may be necessary to angle the camera upwards, causing the verticals to converge dramatically. It is possible to use software to adjust for converging verticals, though verticals should converge just a little unless the photograph is taken from a distance. I find it challenging to create a photograph with angles that look right. CliftonTaylor’s photographs are generally impressive; one wonders how they were taken, and what equipment was used. Some types of old bellows cameras permitted the lens to be tilted or shifted to remove distortion. Shift-lenses for 35 mm cameras became available only in the 1960s and they remain expensive. Lenses also produce optical distortion that turns the straight lines of the real world into slightly curved lines. There are barrel distortion and pincushion distortion, and ‘moustache distortion’, which is a mix of the two. To a degree, this distortion can be corrected using software by hand and the more sophisticated packages can do this automatically. Colour balance is another challenge. The colour of daylight changes according to cloud cover, atmospheric moisture levels and the angle of the sun, affecting the colour of the photographs. Professional photographers use white or neutral grey ‘photo cards’ to provide a reference and enable subsequent correction of the photos, but that is something for the patient person. There is also a debate as to whether or not to photograph in direct sunlight. Up to a point, if one does photograph on bright sunny days and avoid low sun angles, the colour balance question is largely resolved. But close-ups of stone and brick can look rather odd in direct sunlight, and because of the shallow depth of field in close-ups, it is easy to get things out of focus. Because we examine stone and brick surfaces close-up, our binocular vision can easily see the texture of the materials. In photographs that three-dimensional sense is lost: texture does not reproduce well. It would nonetheless be helpful if there were a library of photographs of brick and stone that would enable easy identification in the field. The angle and position of the sun for a particular date, time and year, and the extent of shadows cast by nearby trees and buildings, can be ascertained using freely available websites (such as Shademap). This is particularly useful for planning when to photograph facades that face north. The gatehouse at Oxburgh Hall, North Norfolk (1482) viewed from the north west Sherman’s Hall, Dedham, Essex (new front, c1735) At the Bell Inn, Minster, Thanet, Kent, the chimney and the garden wall have gone, and the scene is cluttered with cars, a van, white lines, floodlights, signs and hanging baskets. All that is left of a row of flint cottages at East Raynham in North Norfolk (seen in a detail, below), demolished in the summer of 2024.
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