What is Infrared Photography?
Infrared photography is photography of near-infrared light in the 680nm to 1200nm range. This is different than thermal imaging, which images far into the infrared spectrum. Infrared photographs produce some very distinct effects which make them appealing to photographers such as white foliage for landscape photography and smooth skin for wedding portraits.
Digital Infrared vs Infrared Film
Because infrared is not visible to the human eye, shooting infrared poses some troubles. When using infrared film, it can be difficult to properly focus the camera since infrared focuses differently than visual light. The amount of infrared light in a scene is also independant of the visible brightness, so one must take multiple exposures when using film. Since IR film is sensitive to both visible and infrared light, an opaque filter must be used on the lens as well. This forces the photographer to place the camera on a tripod, compose his shot, and then attach the filter. Not only is the film hard to develop afterwards, but 35mm infrared film is no longer manufactured.
With digital cameras, infrared photography is still possible without any modification. Digital cameras are sensitive to infrared light and contain an internal filter that blocks infrared light. For normal photography this is a good thing because it allows for accurate colors, however, if you are trying to take infrared pictures this poses a problem. Infrared photography is possible with an external infrared filter, but when doing this keep in mind there will be two filters infront of the sensor, one blocking infrared light, and the external filter blocking visible light. These two filters tend to cancel each other out, requiring very long exposure times to get a properly exposed picture. The external opaque filter also makes composition on a DSLR difficult and requires the use of a tripod for the long exposure times This makes it impossible to take clear infrared pictures of moving objects.
Converted Digital Cameras vs External filter
Normally infrared with a digital camera is taken using an external filter that blocks visible light. This is counter productive since digital cameras have an internal filter that blocks infrared light. As a result, there is very little light getting to the sensor so taking pictures requires a tripod and long exposures.
With a fully converted infrared camera, the camera’s internal hot mirror is removed and replaced with a filter that only lets infrared light through. This makes a camera much more sensitive to infrared, allowing handheld infrared shots to be taken with normal exposure times and low ISO. There is no more need for filters infront of the lens, allowing for easy composition and lens switching. A converted digital camera is the only way to take good digital infrared portraits as the subject no longer has to stay perfectly still for a long exposure. Putting the infrared filter inside the camera instead of on the lens allows you to use the autofocus as well.
Why convert to full spectrum?
In a full spectrum conversion, the camera’s internal hot mirror is removed and replaced with a clear glass filter. This makes the camera sensitive to UV, visible, and IR light. This is a great option for someone who does not want a camera devoted to IR. By using various external filters, the camera can take pictures of regular light, infrared light, UV light, or any other combination of these. Most hot mirrors also have an anti-aliasing filter built in, so by removing this filter pictures will be sharper.
Uses of Infrared and Full Spectrum Photography
Infrared photography has a strong appeal for fine art photography. Infrared photography looks very surreal and otherworldly, with trees taking on a bright white or yellow hue, and skies a red or blue hue. Leaves appear frozen over and skies take on dramatic colors in both black and white and color photography. Take a look at our Customers page for galleries taken with our cameras.
Infrared photography is also a very usefull tool for a wedding or portrait photographer. Skin looks much softer and most blemishes dissapear. For portrait photography, you can imagine the difficulty of trying to take a picture with a long exposure, but with a converted camera, infrared photography is as easy as taking a regular photo, just compose and shoot with no blocked viewfinder or long exposures.
Besides the appeal for fine art photography, infrared and full spectrum photography are used in other fields. Many materials and dies do not look the same in visible light and infrared light. This can be used to spot camaflouge, spot counterfeit money, and see through spills for document recovery.
Full spectrum photograhy is popular in the field of physics for taking pictures of the stars as some stars are only visible when viewed in the IR or UV spectrum.
There are also countless other applications for full spectrum photography including biological plant population survaillance, medical applications, forensics, greater light sensitivity for low light shooting, game hunting, as well as many others.