Infrared photography, The bridge over the kings river, kells, Co Kilkenny

Infrared Photography, The bridge over the kings river

An infrared shot of the bridge that crosses the kings river at kells, Co.Kilkenny. This images is taken using a camera on a tripod that has an infrared (IR) filter over the lens.

Because these filters block anything but light in the infrared wave length, composing the shot is performed with the filter removed and then put in place, you cannot see anything through the viewfinder with the filter attached. Focusing the shot is not made simple as the focus point of IR light is not the same as visible light so focusing after you attach the filter will not work.

Older lenses such as Nikon Nikkor AIS lenses had a red (R) marking on them so that you could see the focus point for IR light at any given focus length of the lens, if the lens was a zoom lens the marking changed as you moved the zoom position. I still have some AIS lenses so they get used for this purpose.

Another option for IR photography is to purchase a digital camera converted to photograph only IR light, focusing however will still be down to you. The use of a small lens aperture such as f22 will help with focus errors but you must remember to lengthen your exposure time, yes the cameras exposure meter will not work on IR light so you’re into full manual mode.

Because IR light levels are very low you will need to use both a tripod and a slow shutter speed in order to get a sharp and well exposed shot. The use of software such as photoshop is not needed if you can get the correct exposure directly from the camera. One thing that will become clear is that in a colour exposure only red light is recorded, so if you intend to print directly to your printer then change your camera setting to black and white or set your printer for a monotone print.

This type of photography is great fun and can produce some great results, such as the water in this image. It took some 8 seconds to get the correct exposure so the water movement has merged to produce a mirror like effect.

The feeling you get must be the closest thing to the original feeling that Landscape photographers had when they set-up very large format cameras in the field.