Watch the above video for a live footage guide of how to set up your camera for infrared photography and see some comparisons between different filter strengths.
I must admit, I’ve become a little obsessed with infrared photography. It presents a whole new way to see through the lens—potential scenes that you would have previously dismissed can suddenly spring to life, and suddenly you find yourself framing your shot around a subject you wouldn’t have glanced twice at if you were taking a regular photograph.
The principle is very straightforward: ordinarily, your camera blocks most infrared light from hitting the sensor. The amount of infrared light blocked can vary from camera to camera, which is important to consider if you’re not thinking about getting a converted camera body solely for infrared photography (more on that later).
We simply reverse this process and expose the camera sensor to only infrared light. Most infrared light is invisible to the human eye since its wavelengths are longer than those of visible light, and so when we capture this light with our camera the results are very different to a regular photograph.
Key Points
Wavelengths
Infrared light occupies the wavelengths 700nm (nanometres) through to 1mm (millimetre). Infrared filters that you can put in front of your lens come in different ‘strengths’ or values—for example, an 850nm filter will block all wavelengths below that value. A 720nm filter would be regarded as a standard filter to start out with, as its cutoff is just above the wavelength where infrared starts.
A 590nm filter will let in all infrared light as well as some visible light from the red spectrum—this is referred to as ‘false colour’ and is commonly used to produce more colourful infrared shots. Photographers have coined the term ‘goldie’ to refer to the reddish golden look that can be produced with this false colour infrared photography.
Conversely, a 950nm filter will only let in infrared light from the very top of the infrared spectrum—you would only really use this filter value for conversion to black and white, since the resulting image will be very monochromatic. It will also severely reduce your shutter speeds (even with a converted camera which is explored below), meaning it’s suitable for long exposure infrared photography.
An 850nm filter is somewhere in the middle—it sits well above the beginning wavelength of 700nm and so will only capture a portion of infrared light, but it’s not as aggressive as a 950nm filter and so will allow faster shutter speeds. Again, you would typically use this filter for black and white conversions.
Using filters
Filters are a cheap and inexpensive way to experiment with infrared photography. You simply attach a filter to your lens and shoot as normal—well, sort of.
Because cameras mostly block infrared light, you’ll find you have to use long shutter speeds to achieve a properly exposed image. Whilst this sounds fine, you also need to consider that cameras differ in how aggressively they block this light.
For example, I primarily shoot on an Olympus E-M1 mk2 and its infrared block is fairly mild—with a 720nm filter, I can achieve decent exposures with a shutter speed of 20 to 30 seconds on average.
On the other hand, I tried out a Panasonic GX9 and struggled to get a decent exposure with anything less than 60 seconds.
Further to that, you also have to consider focusing—because infrared light is a different wavelength, it focuses at a different point. This means you can’t expect to focus the camera without the infrared filter in place and have a sharp image when you put the filter on. You’ll need to adjust the focus to compensate—this is why mirrorless cameras and cameras with comprehensive live view functionality have a big advantage here, since you can use focus magnification and focus peaking to manually focus.
The severe reduction in light (since infrared wavelengths are normally blocked) means autofocus will really struggle, and it’s still a challenge with manual focusing—the live view will be noisy, making it harder to check if your shot is in focus. You can see this quite clearly in the video during the first example of the waterfall scene.
Another issue you’ll have to deal with when it comes to long exposures is hot pixels—these are sometimes remapped by RAW development software if you shoot in RAW (which I’d definitely recommend for infrared photography), but you’ll still need to be aware of them and be prepared to retouch if necessary.
Using a converted camera
This is definitely my favourite approach. There are various sites that will perform infrared conversions if you have a second camera body. Alternatively, you can usually find cheap converted camera bodies on eBay. For the video, I used an Olympus EP-1 that was converted to infrared and had a 590nm filter fitted, as I prefer false colour infrared imagery.
You don’t have to settle for a particular filter strength, though—you can also go for a ‘full spectrum’ conversion where ultraviolet, visible and infrared light are all exposed to the camera’s sensor. It’s then up to you to control which type of light the camera sensor captures using filters.
Regardless of which option you choose, there are two major benefits to using a converted camera:
- You no longer have to use filters to capture infrared light. It sounds like a small point, but the ability to just change lenses and shoot at a moment’s notice is quite liberating.
- Since the camera doesn’t have an infrared block in front of the sensor, you can now shoot handheld at regular shutter speeds! This is by far the best reason to consider a converted camera as it will encourage you to experiment more with infrared photography, since you can just pick up your camera and shoot.
- Referring to the challenge of focusing your lens mentioned above—it’s no longer an issue, since the infrared block has been removed. This means your autofocus capabilities will work fine, and you can also get a much clearer live view if you prefer manual focus.
White balancing
Regardless of whether you’re shooting with a filter or a converted camera, I would strongly recommend using a custom white balance rather than leaving it on auto.
As explored in the video, the reasoning behind this is that auto white balance will tend to be heavily biased to a particular channel—for lower value filters especially, e.g. 720nm or 590nm, the image will usually have a heavy red cast. This means that you’ll be underexposing the blue and green channels just to stop the red channel from clipping, which can result in these channels being noisier. You can always white balance in post, but it’s worth getting it right in camera as you’ll end up with a cleaner image.
An easy way to correct the white balance is to use a feature that most cameras have, which is to take a picture of a subject or area that represents white. Many infrared photographers will white balance off foliage if they’re trying to achieve the ‘blooming’ foliage look, and this is a good starting point as it will usually neutralise and balance all three colour channels. You can also use a white balance card too.
Infrared and Affinity Photo
Affinity Photo will successfully process RAW images with an extreme white balance, and you can easily perform channel swapping and other techniques that are common to infrared photography (all the images in this article and the video were edited in Affinity Photo).
A common issue with infrared photography (explored above) is not white balancing and leaving the camera’s white balance on Auto, which often results in a heavy colour cast. This is also covered in the video, but provided you shoot in RAW, Affinity Photo’s Develop Persona allows you to use its White Balance Tool to easily correct these images. It will perform the necessary white balance shift, regardless of how extreme it needs to be, meaning you don’t have to resort to .dcp profiles and other trickery to correct your images.