Our Tips & Tricks series aims to give beginners, amateurs and professionals alike more ways to approach different aspects of photography and videography. For each installment, we’ve enlisted the expertise of our MPEX staff (or friends of the store) and have received their feedback on method and equipment.
This special tips and tricks post on infrared photography comes courtesy of hometown hero Aaron Sheldon, who, in addition to leading our photo walks this summer, happens to be an infrared evangelist and a darn good infrared photographer. Read the post, then check out more of Aaron’s work at his website.
What is infrared photography?
Digital Infrared image capture is the capture of light in the near-infrared spectrum. For those like me who didn’t pay as much attention in science class as they should have, these are wavelengths of light outside of the visible spectrum (700-900 nanometers in length). The amazing thing to me about infrared (IR) capture is that by simply attaching a filter to a regular DSLR camera, you are able to capture images almost surreal in nature. I have always thought of it as being able to see into an alternate dimension where everything is the same except for the light waves we consider to be visible.
What can you shoot with an infrared capture? Just about anything that you shoot with a regular camera. How you go about it is a different story. Infrared light waves do not react like visible light. Rather than reflect off of surfaces, it penetrates the surface and radiates. Also, IR light’s fall-off is much more dramatic than visible light, which makes it perfect for very contrast-y black and white images.
There are two different ways to capture IR light with a DSLR:
1. Use an external light blocking filter, or
2. Convert a DSLR to only allow IR light to strike the sensor.
Let’s start with using an external filter, which is the cheapest and easiest way to experiment with IR capture and is how most photographers start out.
To capture IR light with a regular DSLR and an IR filter, the first thing you need to do is determine how sensitive your camera is to IR light. All image sensors are sensitive to IR light. The problem is that when captured with the visible spectrum, IR light waves can affect auto-focus performance and color quality by over saturating the red channel. To keep this from happening, manufacturers install an IR cutoff filter over the image sensor. It is part of the anti-aliasing filter assembly and effectively blocks a large percentage of infrared light from the sensor.
The reason we are still able to capture IR light with that IR cut-off filter in place is that every manufacturer uses a different IR cut-off filter (also called a HOT filter) and, like any filter, there are many different levels of strength and quality. Some cameras have a very strong filter which lets a very small amount of IR light through. Others use weaker filters which let more IR light through. I like to compare it to a pasta strainer: the smaller the holes, the fewer pieces of spaghetti fall through into the sink, but the longer it takes the water to drain through.
So how do we test infrared sensitivity? With the most important piece of electronic technology invented in the past 100 years: the television remote. Your TV remote operates by sending a beam of IR light from the remote to the TV set. To test your camera, turn on live view and aim the remote into the lens of the camera and then press a button on the remote—any button, doesn’t matter which one. If the IR cut-off filter is letting IR light through to the image sensor, you will see the IR LED bulb on the remote glowing from very pale purple to a very bright white. The color determines how much IR light is getting through. The brighter that color is, the more IR light is getting through, and the more IR light that’s getting through, the faster the shutter speeds you will be able to use.
Now that we know how sensitive your camera is to IR light, the next step is to go to your favorite camera retailer and ask them for an external IR filter. The two most popular external filters on the market are standard screw-on filters and “drop-in” filters which “drop-in” to a filter holder that is then attached to the business end of the lens. Both types have a very dark (nearly opaque) red piece of glass or plastic which will block out visible light and let the longer IR light waves through. The filter is very hard to see through. Once you compose the shot and set your autofocus, you then, carefully, attach the IR filter onto the lens without affecting the focus or position of the camera. Drop-in filters like the Cokin filter and holder system makes it a bit easier. Similar to regular filters, you do have to compose and set autofocus before attaching the filter but, here is the beauty of the system, to attach the filter you simply slide it into the holder already attached to the lens.I have used both kinds and prefer (and currently use) the Cokin P mount holder with the P.007 infrared filter.
Metering with infrared is a bit different than with visible light. As I said earlier, the camera manufactures try to keep IR light from being captured and, because of that, they build their in-camera meters to react only to the visible light spectrum. For the novice IR photographer, this means a whole lot of guessing. Using live view with the hybrid autofocus systems, I do find that newer cameras (Canon and, very surprisingly, the Fujifilm X100S) get it right more often than they get it wrong, as long as the exposure is 30 seconds or less. Regardless, guessing on a proper IR exposure is dependent on the thickness of the IR blocking filter, the quality of light, the strength of the IR filter you are using and what you ate for breakfast. But seriously, it’s all about getting used to how your specific camera sees IR light, and once you have shot a couple hundred exposures you will have a pretty good idea of what settings you will need to use to get a good exposure.
So, we have an infrared sensitive camera, we have attached a quality infrared filter (either screw-on or drop-in/Cokin), and put the whole thing on a tripod. What’s that? Why the tripod? That’s both the blessing and the curse of using an external filter – long shutter speeds. Really, really long shutter speeds, in fact–usually 3-30 seconds if you are in bright sunlight (the range is based on the size of aperture you are using). With long exposures, you get some very creative captures if any type of movement is happening. The downside is that if the subject is something that moves or if there is a breeze, your photo is going to be blurry.
What if you don’t want motion blur, don’t want to have to carry around special filters, use a tripod or do long exposures in the middle of the afternoon on hot sunny days (the best time for IR photography with an external filter)?
Converting a Camera for IR-only Capture
If you want to capture IR images as effortlessly as you do visible light images, you will need to have a camera converted. “Converted” means removing the IR cut-off filter from your camera’s image sensor and replacing it with a visible light blocking filter. This allows your camera to capture IR light using considerably faster shutter speed because the IR light waves no longer need to fight their way through the IR blocking filter on your sensor.
Converting a camera to IR-only is an easy process if done by a professional. I have had three cameras converted by LifePixel, who, in my experience, are the best in the business.
Speaking of research, you will need to do some. Each company that does conversions offers a variety of different strength filters which affect how much infrared light is captured. LifePixel has an amazing amount of information about each conversion, including full-resolution image files from each type of filter they offer and the best way to post process your infrared images (including, if you want, the surreal blue sky effect that infrared photography is known for).
LifePixel also offers a DIY service where they sell you the filter so you can attempt the conversion yourself. Unless you are very experienced with disassembling your camera, and have a clean room to insure no dust particles get trapped between the filter and image sensor, I would leave this job to the pros.
There is one other way to get started with IR photography: Rent an already converted IR DSLR from MPEX. The rental department currently has IR converted cameras made by both Canon and Nikon, and their rental rates are very reasonable.
Tips & Tricks for Capturing IR Images
Use a custom white balance.Infrared capture using regular white balance produces images where the only color is red. To be able to gauge proper exposure and contrast it is best to set a custom white balance each time you shoot.
Compose in-camera with a filter attached. The Live View feature built into most current cameras can allow you to meter and focus with an external IR filter attached. Your final image might not look exactly as what theLCD shows before capture, but it gives you a good starting point without having to do a series of long exposures while dialing in the proper exposure.
As for bracketing, I always recommend bracketing your exposures by +/-1 stop due to the way IR light changes. A passing cloud can sometimes throw off exposure by several stops.
Lens Flare and Infrared do not mix. What might be a nice warm fog at the edge of the frame in visible light photography will be a series of stop sign shaped artifact marching towards the center of the sensor.
Hotspots. Certain lenses have special coatings in them to reduce the effect of IR light. When used with an IR converted camera or a camera with an external IR filter, these lens produce a transparent white circle in the center of the image. The rule of thumb is that the more expensive the lens, the more liking it will have this problem.
Do not shoot directly towards the sun (due to flaring). Compose the image with the sun directly behind for full illumination in mid-day sun. For strong shadows and more contrast compose with sun diagonal to the subject.
Speedlights and studio lights put off a lot of IR light and can be used to great effect in portraiture and for interior/architecture images. It does not reflect, and it actually penetrates clothing and sunglasses, rendering them see-through. It also sees through most make-up (except for mascara) and hair color.
If you are using an IR-converted camera which has Live View you can even use it as a night vision camera. Several manufactures make small infrared LED light packs which, even though they are small in size, will light up a very large room without any visible light (this came in very handy when I needed to check on my newborn son at night without turning on the lights).
I hope you have enjoyed this post and want to give infrared a try. Just remember that IR light is totally different than visible light and takes some practice to do well. Once you know how your camera reacts to IR light, you will be surprised with the images that you will be able to capture. If you would like to learn infrared from a professional, I do offer individual lessons on infrared photography from set-up all the way through to image processing. Please visit my website for more information.