I’ll take a break today from my usual beginner tips to write about a rather underutilized area of digital photography. I have always been fascinated by the images professional photographers would capture using infrared film. They create such a surreal effect; it’s difficult not to be sucked in. When I made the jump to digital photography in the early 2000s, I realized that I was able to take infrared images with only minimal adjustments to my existing equipment. Today I’ll go over a few of the basics of IR photography.
Let’s start with the basics. There are two bands of light which are invisible to the human eye. Infrared and ultraviolet fall far enough to the ends of the spectrum that we are unable to perceive them without the aid of special equipment. Luckily, your camera is not limited in this way.
If you are using a film camera, infrared (IR) photography will require that you purchase IR film and an IR filter and possibly that you make adjustments to the camera itself. IR film and filters used to be available at most photography stores (Note that I do not mean your local CVS. That’s a drug store, NOT a photography store.), but nowadays they may be a little harder to find. In order to find my own Hoya R72 filter, I had to track down an antique camera store two cities away and pick one up there. You can, of course, order just about anything over the internet if you are willing to wait for delivery. I’m just impatient. Before you go out and purchase any new equipment, check that your camera does not use infrared lights to check film advancement. Certain Canon and Minolta models use these lights to check that your film had advanced properly as average film is not sensitive to infrared radiation. More camera models may have been produced using this technology since I last checked. These lights will expose infrared film and make the camera useless for IR photography without some modification. If you do have a camera capable of IR photography, look for an IR filter and some IR film. I personally use a Hoya R72 IR filter. Other filters that I have used in the past are the Wratten 87b, and Hoya R90.
Can Your Camera Support Infrared?
Every digital camera ever produced has been capable of taking IR photographs. This is because digital image sensors are sensitive to light beyond the visible spectrum. Why, then, do we not see IR images coming from our cameras? When a digital camera is produced, the manufacturer places a filter over the image sensor to remove IR light before it can be processed. Each company uses slightly different filters with varying degrees of efficiency. The result is that some cameras are better than others for IR photography when used off the shelf. A good way to test your camera’s potential is to take a TV remote (or some other remote that uses an IR beam), point it at your camera from about one foot away or less, press any button, and see how well your camera is able to read the beam on its screen. This test is easiest on point and shoots as most are capable of using their screens instead of a viewfinder. More and more SLR models come with a “Live View” mode today, but older models will require that you actually take a few photographs in order to run this test.
Both of these shots were taken at a distance of about 3 inches from a TV remote. The image on the left is from a Panasonic Lumix DMC-LX1. The image on the right is from a Casio Exilim EX-S880. As you can see, the filter on the EX-S880 is inferior to the DMC-LX1. As a result, I can actually do hand-held IR shots using the EX-S880 by holding a filter over the lens. This is impossible with the DMC-LX1. This test will tell you the ability of your digital camera to take IR shots without using a tripod. Most people will need either a tripod or a modification to their camera.
The Infrared Filter
IR filters are black, or nearly black. They usually make it impossible to arrange your image. Unless you camera has a viewfinder that is not linked to the lens, you will be unable to see what your camera is looking at. In addition, your camera will have trouble focusing and, in the case of SLR cameras) will be unable to properly meter the scene.
If you want to avoid these kinds of problems, you can modify your camera or have it done by a company for a few hundred dollars (USD). The modification involves opening your camera’s body and removing the IR stopping filter from over the image sensor. The filter is then replaced with a IR filter which is the equivalent of the Hoya R72, R90, or some other IR filter. The good news is that without the IR blocking filter, you will never need to attach an external filter and you will not need to expose the image as long: Hand-held shooting will be possible. The bad news is that your camera will only be able to do IR work. Another piece of good news; since the IR filter is now over your image sensor, you will no longer have to worry about blinding yourself by looking through your viewfinder!
At the moment, I do not wish to spend 300 dollars to have someone do work I can do myself, nor do I wish to open one of my current cameras. Until I have time to go hunting for a decent used high end point and shoot to disassemble and adjust, I’m using my Canon EOS 450D (XSi / KissX2) equipped with a Hoya R72 filter. The 450D comes with a fairly good IR stopping filter over the sensor. While this is good for some people, it is irritating for me as it means that I need longer exposure times reaching over 3 minutes in some cases.
Shooting with an IR Filter
If you cannot see the scene you are photographing when using an IR filter, how can you compose your images? As annoying as it is, the simplest approach is to compose your image without the filter and then attach the filter afterward. Once you have composed your image and focused it, attach your IR filter, back the focus off VERY slightly, set your aperture to about 7 -10 (This step can be skipped if you want, but it will help to ensure that your subject remains in focus), and expose your image for 10 seconds or longer. Depending on the image, the necessary exposure time could be 10 seconds, 30 seconds, or a few minutes.
The initial image will be very red / purple. By fixing the white balance, resetting the levels, and reversing the red and blue channels in Photoshop, you can turn this into a very appealing color photo. The other, more traditional, approach is to go black and white.
After a few adjustments, we have a color IR image captured using a Hoya R72 filter. Notice how the foliage turns white under IR light. Skies appear darker than when using traditional imaging and shadows often have a more appealing texture.
Here is another copy of the same image converted to black and white. Notice how rich the shadows have become in this image. Infrared photography can really bring out the beauty of a black and white scene. Clouds stand out against darker skies, water becomes calm and reflective, and shadows become richer. It is for this reason that a lot of architectural photographers use IR photography.
The image on the left was taken using visible light. The image on the right was taken using IR photography. Notice how the IR photograph is more visually appealing than the traditional photograph. The sky is darker, the foliage is lighter (thought not as white as it would be in most IR photographs), and the shadow gradations on the towers appear richer than they do in the image on the left.
IR photography is more time consuming and lends itself more to landscape photographers than to portrait photographers (Unless you’re willing to tear apart an old camera and remove the IR blocking filter). If you’re willing to put in the time to get that perfect shot, a solid IR filter and a bit of planning will put you well on your way to capturing a memorable image.