Coverging verticals may be easily corrected, but embracing them can reap its own rewards
At some point, every photographer encounters the issues surrounding perspective control and converging verticals.
We are restricted physically by our surroundings and by the equipment we use, and often the two work together to compromise the image we are trying to achieve.
Sometimes these effects may be unintentional but so slight as to be insignificant. Other times they may detract from the image, making the subject appear unnatural.
But they can have many creative advantages, too, and understanding the subject allows us both to correct those images we deem wrong in some way, and get them right in the first place.
Image: Converging verticals approaching from a number of directions can help lead the eye through an image
Coverging verticals: In Camera
Image: The increased angle of view a wideangle lens affords can be useful when dramatic converging verticals are desired, but using such a lens close to the subject can also make barrelling appear more pronounced. This is easily corrected in post-capture processing
Whether we are photographing a building or details close up, the problem of converging verticals occurs for the same reason, which is down to the relationship between the camera and lens, and the subject being photographed. Different photographic equipment can help control the degree to which this effect is noticeable, but it’s important to remember that this isn’t an optical defect, but something that varies according to viewpoint.
We view a photographic print and the world around us in different ways and, when representing a three-dimensional space in a two-dimensional format, the issue of perspective becomes important.
While the effects of converging verticals and buildings appearing to be tilting backwards or forwards can be seen easily in reality, we can appreciate that these aren’t likely to collapse simply because it seems that way. When looking at an image, however, such things become more noticeable and can somehow look wrong.
Architectural photography is perhaps the easiest genre by which to understand converging verticals, with its defined lines and shapes being especially susceptible to the effect. For many this is perhaps where the effect is most frequently experienced.
A building being photographed from the ground will typically require the photographer to tilt the camera upwards to fit it into the frame. Doing this puts the focal plane at an angle to the subject and, as the photographer will naturally be closer to the bottom of the building than its top, there will be a difference in magnification between the two points. These factors are what cause linear details to appear to converge.
This principle applies equally when a building is being photographed from a height or from its side, with the extent of the effect changing as the viewpoint is altered, and with it the resulting image and its impact.
What can be done?
The control over converging verticals afforded to the photographer varies between camera systems, but it is largely down to the differences in mechanical construction. The flexible bellows and adjustable front and backs of view cameras offer immediate and simple control over perspective, while further control in the darkroom over the relationship between the enlarger and paper allows final corrections to be applied.
Owing to mechanical and economic constraints, consumer-targeted digital systems don’t offer such control as standard, meaning the user requires a tilt-and-shift lens with which to adjust perspective. While such lenses are useful, their price puts them out of the reach of many, making another solution necessary.
By moving further away from a subject – again, a building, for example – the magnification ratio between its top and bottom decreases, and with it the strength of the effect.
This won’t always be possible, however, which is where a wider lens becomes useful. Using one won’t change the perspective, but as it allows for more to fit into the frame, it means the camera won’t need to be tilted as much and so its focal plane will lie more parallel to the subject.
The key to avoiding converging verticals is to position the camera’s sensor or film parallel to the subject, which, with architecture, is usually achieved by having the camera completely upright and not tilting up or down. Some cameras now include an in-built level, which allows you to accurately position your camera in relation to a subject, but for those without this feature a hotshoe-mounted spirit level can be used to achieve the same goal.
Images: This series of images shows how distance affects converging verticals. For each image, I moved 15 paces back from my previous position and zoomed in so that the building was filling the same proportion of the frame each time. As the image was taken from greater and greater distances, the effect of converging verticals became less apparent.
Sometimes it isn’t possible to move to the most appropriate distance, and converging verticals will still affect your image.
Adjusting your composition to include unnecessary peripheral detail around the edges of the frame can help in such circumstances, as these areas can be cropped out later in post-production.
If this isn’t possible, consider whether what it is you’re trying to avoid would work well in an exaggerated form. Shooting a building from an extreme angle, for example, can produce dramatic verticals leading up to a vanishing point.
Although viewpoint is a decision largely down to the photographer, some DSLRs, like the Nikon D5000, offer a post-processing function as part of their retouching options. As this process works on images post-capture, the corrections are applied in the same way as they are in image-editing applications, whereby the image is stretched in some way to compensate for the effect. This has both advantages and disadvantages, which are explained in our other article on converging verticals found in the related articles section of this page.
While converging verticals are often thought about in terms of how they affect architectural detail, other types of photography, like macro and abstract close-ups, can also show the effect.
With a little imagination the effect can be created using many otherwise mundane subjects: a set of venetian blinds, for example, can be used to create an image with a vanishing point with converging horizontals.
Image: Converging verticals can be used creatively in abstract images, such as in these two examples
Vanishing point describes an effect where lines converge in an image and appear to vanish into the distance: a long stretch of road extending into an empty landscape, for example. It’s commonly employed with long exposures, such as with light trails created by cars on a motorway, and when used in architecture it can serve as a strong compositional device, particularly when the lines are created by a variety of contrasting sources.