The Essentials of Digital Infrared Photography

By Randy Juster Back to

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I got interested in infrared photography in the early 1970s. But the only IR film available at the time, Kodak High Speed Infrared, was grainy and relatively low in sharpness so I was never really happy with the results. One day everything changed. Looking at Minor White’s monograph, Mirrors, Messages, Manifestations, I came across a section, Sequence 10, of infrared photos that were impressively sharp and detailed. It hadn’t occurred to me that infrared film might be available in sizes larger than 35mm. That day I ordered my first box of 4×5 infrared and continued using the product until Kodak discontinued it over 25 years later.

When everything worked, shooting large format infrared was great. But for every wonderful surprise there were an equal number of mishaps and at close to $2 a sheet there were limits to how much experimenting I could do.

Filters
Choosing a camera filter to use with black and white infrared film is pretty straightforward. There is the “standard” IR filter that passes a small amount of visible light such as the Hoya R72 (now labeled RM72), or the similar B+W 092. The other option is the darker B+W 093. I own all these filters, including Kodak’s 87C and the discontinued Hoya RM 90, and where black and white film shooting is concerned the biggest difference I’ve found is the exposure time. Not surprisingly, the 720nm filters that pass some visible light allow much shorter exposures than the 900nm types. It’s true that with a 900nm filter you will often get a somewhat darker more dramatic sky but the RM72 or 092 also perform well when it comes to dramatic skies and exposure times are significally shorter.

Comparing Brands of Filters

For some reason, “equivalent” infrared filters from different manufacturers have never been exactly equivalent—and I can attest to getting slightly different results from them back in the film days. Now with my camera modified with a built-in infrared filter, I don’t use external filters and thus don’t compare them.

The Hoya RM72 or equivalent has been the standard IR filter for as long as I can remember. Some of the folks who convert digital cameras for infrared label them a “720nm conversion” while others simply refer to it as “standard” or “most popular.” So a 720nm filter is as close to “generic/standard/when in doubt/ lowest common denominator” as you’re going to get.

But if you are going to shoot infrared (either film or digital with an unmodified camera and a filter in front of your lens), you have the choice of brands, such as Hoya, B+W, Heliopan and Lee. Hoya notes their RM 72 cuts off visible light below 720 and B+W notes that their 092 filter “blocks visible light up to 650nm, yet passes IR from 730 on up.” In practical use, the results from the RM72 and 092 are very similar in my experience—but if you want to split hairs, not exactly the same.

The popularity of digital infrared photography has brought forth a variety of filter options. It’s certainly worth taking the time to examine comparisons from the companies that do IR conversions. If your goal is dramatic black and white exclusively, you might consider the “maximum” infrared filter conversions. From the infrared filters that are usable for color, there’s no “right” choice but given the amount of control you have in Photoshop, there’s likely no wrong choice, either.

My camera was converted by Life Pixel and has their standard 720nm conversion, which is one of the most popular conversions.

With the arrival of digital photography infrared photographers have the best of all possible worlds. Infrared photography can still be unpredictable but you can now take as many shots as you like, get instant feedback and it costs you nothing.

As shot in modified IR DSLR

After auto-levels

Final, after channels swapped

What you’ll need to make digital infrared photographs:

Budget Setup
• Digital camera with the ability to accept filters.
• An infrared filter–Hoya R72 or similar.
• Tripod or other means of holding the camera steady.
• For black and white photographs, any imaging software capable of adjusting brightness and contrast. For color infrared photographs, you need software capable of isolating the red, green and blue channels in your image.
• A subject that will hold still (important with this budget setup as exposures can be rather long).

Deluxe Setup (What I Use)
• Digital camera that has been modified by removing the infrared blocking filter and replacing it with a filter that passes infrared.
• Software capable of adjusting brightness and contrast and, if you want to try color infrared, imaging software that is capable of isolating the red, green and blue channels in your image.

You may want to first experiment with the budget setup to get a feel for infrared photography. But be aware that it’s somewhat restrictive because exposures will typically be too long for hand holding the camera and your subjects will have to hold perfectly still during exposure.

Point and Shoot vs. DSLR
The good news is that almost any digital camera can take infrared photos. However, modern digital cameras incorporate internal filters that are designed to block infrared. If you haven’t guessed, that’s why infrared exposures with a camera that hasn’t been modified for IR are so long—you are trying to gather infrared light that at the same time your camera is trying to block it!

With digital infrared photography so popular, a number of companies offer services to modify cameras for infrared use by removing the camera’s IR blocking filter and replacing it with a filter that passes infrared (and in most cases, a little visible light as well). With an infrared modified camera the infrared filter is in front of your camera’s sensor and not on your lens. You can shoot infrared images at hand-holdable speeds while your viewfinder remains bright, because you’re not looking through the filter. There is one disadvantage though, and it’s significant. Once modified, your IR camera is an infrared-only camera; there’s no going back.

Your first thought might be to get the smallest, least expensive camera you can find, to save money and not add weight to your camera outfit. But before you invest in modifying a point and shoot camera, I’d suggest getting an inexpensive SLR. The larger sensor in an SLR will give you better picture quality and in addition, because some lenses can cause a reddish “hot spot” (more about this later) when shooting infrared, having a camera with interchangeable lenses is an obvious plus. My digital SLR is an eight megapixel Canon Rebel (Rebel XT). When I bought my first full frame digital SLR, my old Rebel had little resale value so it was a natural choice for conversion for infrared use.

Lake Scene, example of an infrared photograph made on a sunny day.
This is an example of a “tonal merger” when two or more things in the scene are the same shade or color.

White Balance

If you’re considering trying infrared color, you’ll need to set a custom white balance in your camera. If you fail to do this, your images will be in color, but just one color—red. You can easily set a custom white balance by aiming your camera at some green grass. By using this green as the “white” balance, the camera will shift its color to reduce the bias towards red that would give you totally red photos. If no green grass is handy, a sheet of green colored paper from the art store works just as well.

Infrared and Lens Choices
Infrared light comes to a slightly different focus point than visible light. Since I prefer wide-angle lenses and smaller f-stops I’ve never found this to be an issue. But unless you specify otherwise, when you have your camera converted, the focus will be adjusted to the proper offset for a normal lens. If you will only be using one lens and it isn’t a normal lens, you may want to send your lens with your camera to have the camera body’s focus optimized for the lens you’ve chosen. I tried several lenses, including Canon’s 10-22 and the Tokina 12-24, both of which worked well for infrared use. Eventually, I settled on a lens I already had, an Olympus OM 18mm.

A Word on “Hot Spots”
Under certain conditions, some lenses will produce a reddish, lower contrast circle in the center of infrared images. I suggest you Google “infrared hot spot” and you’ll find lists of lenses that are recommended or not recommended for infrared use. I do occasionally get hot spots and deal with them by using either Nik software’s Viveza or Nikon’s Capture NX2. These programs feature a “color control point” which is a soft- edged circle that’s adjustable in size and can be placed over a hot spot and adjusted to raise the contrast.

Tips for Making Successful Images
With a camera that’s been modified to record infrared, the procedures for getting great shots aren’t much different from regular photography, but a little planning can go a long way.

1. Avoid cloudy days. Straight out of the camera, infrared images are almost always low in contrast so I advise to forget cloudy days. I’m not saying it can’t be done, but unless you are shooting portraits, most scenes on overcast days will at best lack the drama we associate with infrared photos. Conversely, subjects that are highly reflective in infrared such as healthy foliage are disproportionably bright in sunlight. In the picture entitled Lake Scene, I saw two spots of sunlight in the foreground and figured they would really pop in infrared.

2. Avoid “tonal mergers.” Tonal mergers (my term) occur when two things in the photo are the same shade or color. I like to photograph architecture and in California where I live, these buildings often have beautiful foliage. That’s perfect for infrared—except if the building is white and infrared turns the plants white as well, it can be a problem. There is really no way around this but with a digital camera you should be able to spot tonal mergers and recompose the photo if necessary.

3. This is the flipside of tip #2 and it applies to all types of photography, not just infrared. To give an image brilliance, position something very dark against something very light—the greater the difference, the better. For example, fresh snow in brilliant sunlight may seem contrasty but it isn’t. The dynamic range from bright white to very bright white is minimal and will result in prints without much snap. But place a dark tree trunk in that snow and things come to life.

4. Bracket your exposures. In the pre-digital days there were many schemes for getting consistently accurate infrared exposures on film, including modified light meters but I never found these to be reliable. Since it costs nothing to take multiple shots I strongly recommend you do so and if you can, pay attention to your camera’s histogram to give you a better idea of your exposures.

Art Deco House Series: Standard DSLR

Results right out of IR modified camera

After auto levels adjustment

Final-after channels were swapped

Processing Your Images

Processing digital infrared images is a simple procedure. But since you are not seeking an entirely realistic look, you can easily spend lots of time trying different variations on the same image.

If your goal is a black and white image, in most cases all you need to do is adjust contrast. To do this with one click in Photoshop, with Image >Adjustments >

Results right out of IR modified camera

Levels and click Auto. Since we’re not after absolute authenticity here, you may want to clip the highlights a little for the most brilliant whites and/or the shadows for more dramatic blacks. But it’s that click on Auto in Levels that brings your image to life by boosting the contrast to a pleasing level.

Infrared color seems to be a controversial subject because some of the wild color possibilities are not necessarily pleasing. Of course, everyone’s taste is different. I’ve arrived at a compromise for my infrared color. I adjust the sky to be a more or less realistic blue and this “anchors” everything else in the picture. The way to do this is a simple red/blue channel swap. Here’s how to do that:

Go to Image >Adjustments > Levels and click Auto. Next, go to Image >Adjustments> Channel Mixer. Choose the red channel and reduce the red slider from 100% to 0%. Then raise the blue slider from 0% to 100%. Now, select the blue channel and raise the red slider from 0% to 100% and reduce the blue slider from 100% to 0%. That’s all there is to it, and since you’ll be doing this channel swap often, I recommend creating an action in Photoshop. If the blue in the sky is not the shade you want, go to Image> Adjustments>Hue/ Saturation. Choose blue from the pull down menu and you can fine-tune the sky from there.

I hope this article will provide the information you need to for a quick start with infrared photography. Whether you use infrared photography for a slightly different take on traditional shooting or as a total departure from conventional photography, the possibilities are unlimited.

SPECIAL OFFER FOR photo technique READERS! photo technique readers get an additional 10% OFF Digital Silver Imaging’s already low price on Infrared Camera Conversions! Visit their website at digitalsilverimaging.com for details or use the promo code PT2013 at checkout to receive this special offer. Offer expires February 28, 2013. 

Resources: Digital Infrared Conversions: Life Pixel-lifepixel.com; Digital Silver Imaging-digitalsilverimaging.com; Filters: B+W-schneideroptics. com; Hoya-hoyafilter.com; Heliopan-hpmarketingcorp.com; Lee- leefilters.com; Vintage filter resources-ebay.com. Software: Photoshop-adobe.com; Viveza software-niksoftware.com; Nikon Capture NX2-nikon.com 


About the Author

Randy Juster
RJuster
Randy Juster is a graduate of Chicago’s Columbia College and worked in the photographic industry for more than 35 years as a Product Manager for E. Leitz, Inc. (Leica) and a Photographic Engineer for Ilford Imaging USA. Randy’s photos have been appeared in numerous books and exhibits, the New York Times and are in the permanent collection of the Smithsonian. Visit his website at decopix.com