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HelpLine By Michael Guncheon

Shoot Infrared With Your Digital Camera

Digital Infrared Effect

Icing The Scan

Polarizing Results

Digital Infrared Effect

I like to take 35mm black-and-white infrared pictures for their wonderful effect. Is there any way to get this effect with a digital camera using filters? I’ve just purchased a Canon PowerShot G2, and I’m amazed at the features digital cameras offer!

H.J. Saunders
Naples, Florida

First, I need to clarify something for those of you who haven’t done any infrared photography. We’re not talking about being able to capture heat patterns of people through walls. The complete infrared spectrum is defined as radiation outside the visible spectrum with a wavelength between 700 nanometers (nm) and 1 millimeter. The part of the infrared spectrum used with infrared film is from about 700 to 925 nm—not heat, so you won’t be capturing thermal images.

Now, back to the question. The image sensor in most digital cameras is a CCD (charge-coupled device), and most CCDs are sensitive to infrared light. However, some manufacturers will include a “hot mirror” in the optical path to prevent infrared energy from entering (a device that lets in visible light, but reflects infrared light). Hot mirrors are typically found only in higher-end SLR digital cameras.

You’ll need to test your camera to see if it can capture infrared images. First, you’ll need some source of infrared radiation. An infrared radiation source is right there by your television or under the couch cushions—your TV remote. Simply point the remote at your digital camera and look at your LCD display while pressing a button on the remote. If your camera can “see” infrared, you should be able to see a spot of light on the end of the remote!

If your camera detects infrared, you’ll need a filter to block out all the visible light. It also helps if you have a black-and-white setting for your camera. Here’s where some experimentation is needed. Try some of these filters in front of the lens to see which gives the best results: Wratten 87, 87B, 87C, 88A, 89B and 93. You should be able to order these filters at any place that sells photographic filters. Many photographers find the 87C and 93 work well, but your particular camera may “prefer” one of the others.

Exposures for infrared are much longer than those for “visible light.” In some cases, we could be talking seconds here, so a tripod is a must. You’ll also have to experiment to get a good exposure (having manual controls or exposure compensation can be helpful).

Another advantage of digital infrared photography is the ability to take two pictures of the same scene: one using infrared and one in visible light. Then you can use your image editor to merge the two images for creative effect.

Icing The Scan

In “Scanning At The Next Level” (Mar./Apr. 2026, PCPhoto), the authors say the dust-and-scratch tools FARE™ and ICE™ shouldn’t be used for scans of Kodachrome or black-and-white, but they don’t explain why. What are the reasons?

Peter Stonitsch
Via e-mail

First, a quick explanation concerning these products. Digital ICE™ is technology developed by Applied Science Fiction (ASF) that has been integrated into several scanners. The main goal is to remove surface imperfections like dust and scratches. FARE™ (Film Automatic Retouching and Enhancement) is Canon’s process for improving the quality of a scan by getting rid of surface defects. (Both technologies use hardware and software to make the corrections; you can’t add them to just any scanner.)

To understand why this process doesn’t work well with Kodachrome or black-and-white negatives, you need to understand what’s going on during the scan. In a typical film scanner, light is transmitted through the film and lands on the image sensor (CCD). Each dye layer of the film affects how different frequencies of light (color) pass through the film, which then gives us the colors of the image. A problem with this process is that if you have an imperfection on the surface of the film, it will be picked up by all of the frequencies of light, making it show up in the scan.

Now comes the magic. Scientists discovered that if you take infrared light and pass it through the film, the cyan, magenta and yellow layers disappear! More importantly, what doesn’t disappear is all of the imperfections on the surfaces of the film.

So by scanning the film with infrared light, we’ve added a fourth channel to the typical RGB output. ASF calls this the “Defect” channel. By comparing the defect channel scan information with the separate color channel scans, the software can selectively remove imperfections from each of the individual color channels.

Back to your original question. With traditional black-and-white film, infrared light shows similar images that a regular scan would pick up. No colors can be compared, so there’s no disappearing act here! In fact, if you select monochrome film in Canon software, the FARE™ technology is automatically disabled.

The good news is that you can still use some black-and-white film with these technologies. If you’ve noticed, I said “traditional” black-and-white film won’t work. Traditional black-and-white film doesn’t use dyes; it uses silver to produce an image. Infrared scanning picks up the processed silver in the film as defects.

If you’ve been shooting with chromogenic film, however, you’re in luck. (Chromogenic film is processed using the same system as color negative film, but you end up with a black-and-white image.) By using this process, chromogenic film doesn’t contain the processed silver that causes the infrared scanning problem.

Kodachrome is a different story. Color dyes are added to Kodachrome during the development process. One of these dyes, a cyan color unique to Kodachrome, causes problems with infrared scanning. This infrared scan can misinterpret details in the cyan part of the image as defects. So, if you scan Kodachrome using Digital ICE™ or the Canon system, you might lose detail in these areas of your image.

Polarizing Results

I bought a digital camera to go along with my 35mm gear. One of the tools I use is a polarizing filter. It has always been recommended that I use a circular filter instead of a regular one. Since I’ve been using my new camera, I miss having a polarizer. Do I need a circular one or regular one?

Russell B.
Via e-mail

The basic job of a polarizing filter is to block polarized light. You’ll find polarized light in reflections and in scattering of light in the atmosphere. You can see the effect of a polarizer by shooting the surface of a body of water. When you turn the adjusting ring on the polarizer, some of the reflections will disappear. You’re adjusting the amount of polarized light entering your lens.

As manufacturers of 35mm SLR cameras began adding more sophisticated through-the-lens metering systems and autofocus technology, linear polarized light started affecting how these cameras worked. This is where circular polarizers came to the rescue. Circular polarizers (which have nothing to do with the shape of the filter) are made by taking a standard linear polarizer and adding a bit of optical wizardry called a quarter-wave plate. By adding this to a linear polarizer, the light entering the optical system won’t cause problems for the autofocus or metering systems.

As for digital cameras, the use of a circular polarizer should only be needed with digital SLRs. While a circular polarizer will work with any digital camera, you should be able to use either type for non-SLR digital cameras. Circular polarizers may be easier to find, however.

If you have any questions, please send them to HelpLine, PCPhoto Magazine, 12121 Wilshire Blvd., Ste. 1200, Los Angeles, CA 90025 or [email protected].Visit our Website at pcphotomag.com for past HelpLine columns.