Monday, 19 May 2014

Infrared Architectural Photography

Infrared film was used by professional architectural photographers for a long time to make images of buildings. Infrared photography could produce interesting pictures, especially in bad weather; it could cut through haze, add contrast and produce pure black skies with white clouds thus creating a very dramatic scene.

Infrared Architectural Photography
Photo by: Paul Bica

Just as we mentioned when discussing the use of fisheye lenses for photographing architecture, infrared is also used more for effects. It has the potential to transform seemingly uninteresting structures to something very dramatic that screams for the viewers’ attention; ordinary scenes take on a dreamy look when shot in infrared.

Infrared is also part of the electromagnetic radiation that the sun emits. The digital sensors used in our cameras are also sensitive to infrared and so they could record them. But for general purpose photography, recording the infrared radiation along with normal light only serves to deteriorate the quality of the picture. So a special infrared filter is placed in front of the digital cameras sensor to filter out those rays. One could do infrared photography either by placing an infrared filter over the lens (this filter cuts out all the visible light and only let the infrared rays through) or have the infrared filter in the camera removed to convert the camera for infrared photography. In the second case, the modified camera could then only be used for infrared work.

infrared architecture photography
Photo by: Adrien Sifre

There are certain facts that one needs to be aware for before trying this technique. First thing is that not all surfaces reflect infrared rays equally, this is the reason why those images have a rather ghostly feel to it. Those surfaces that reflect more infrared radiation, for example leaves (chlorophyll in green foliage to be precise) appear white and those that reflect less appear dark.

The level of infrared radiation is not proportional to the brightness level of the visible light, they tend to be stronger during early mornings and later afternoons.

infrared photography
Photo by: Jes

The cameras light meter could be easily fooled when shooting infrared so it is recommended to set your exposures manually via trial and error. One technique is to boost your cameras ISO to its highest and set your exposure to get a properly exposed picture, one you get it right, decrease the ISO and compensate by increasing equal stops in shutter speed. This helps you speed up the process by not having to do the trials with long exposure times.

Wavelength of infrared light is longer than normal light as a result there could be a slight shift in focus when doing infrared work, (effective focal length of lens is greater for infrared than for visible light). Best practical solution is to stop down the lens to increase the depth of field so your subject falls well within the depth of field available and is thus rendered sharp.

Related Reading

  1. Panoramic Architectural Photography
  2. Using Reflections in Architectural Photography Compositions
  3. Creative Composition Tips for Architectural Photographers - Framing the Building
  4. Composition Tips for Architectural Photographers - Balancing Colors in an Image
  5. Tips for Photographing the Progress of a Building from Construction Through to Completion