Infrared Photography Techniques and Results

Venturing beyond the colors our eyes can see opens up a whole new world for photographers. Infrared (IR) photography isn’t about capturing heat signatures like thermal imaging; instead, it captures light just beyond the red end of the visible spectrum. This invisible light interacts with subjects differently, leading to often surreal, dreamlike images that stand out from conventional photos. Foliage turns white, skies become dramatically dark, and the familiar world takes on an ethereal glow.

Understanding the Unseen Light

Visible light, the rainbow spectrum we perceive, is just a small part of the electromagnetic spectrum. Infrared light sits right next to red, with longer wavelengths. Digital camera sensors are actually inherently sensitive to this near-infrared light, as well as visible light and even some ultraviolet. However, manufacturers intentionally place an internal filter, often called a hot mirror or IR-cut filter, directly over the sensor. Its job is to block most IR (and UV) light, ensuring the colors you capture look natural and match what you see. To practice infrared photography, you need a way to bypass or remove this limitation, allowing the sensor to ‘see’ the IR wavelengths while simultaneously blocking most visible light.

Methods for Capturing Infrared

There are primarily two ways photographers approach capturing the infrared world: using external filters on a standard camera or using a camera specifically modified for IR work.

Using Infrared Filters on Standard Cameras

This is often the entry point for many photographers curious about IR. It involves attaching a screw-on filter to the front of your lens that appears opaque or very dark red because it blocks most visible light while allowing infrared light to pass through. Common filter strengths are designated by the wavelength they start passing light at, such as:

• 720nm (Standard IR): Blocks most visible light, producing classic high-contrast black and white IR images or false-color images with white foliage and dark skies after processing.
• 850nm (Deep IR): Blocks almost all visible light, resulting primarily in black and white images with even stronger contrast and IR effects.
• 590nm or 665nm (Enhanced Color IR): Allow some visible light through along with IR, enabling more vibrant and varied false-color possibilities post-processing, often called ‘Super Color’ IR.

The Process: Shooting with these filters on an unmodified camera requires long exposure times, typically ranging from several seconds to even minutes, depending on the filter strength, lighting conditions, and camera settings. This necessitates using a sturdy tripod to avoid camera shake. Focusing can also be tricky. Since infrared light focuses at a slightly different point than visible light (a phenomenon called IR focus shift), autofocus often fails or is inaccurate. Manual focusing using live view (zooming in to check sharpness) or estimating the focus adjustment is usually required. Some older lenses have a small red dot or line as an IR focus index mark to help with this, but it’s often an approximation.

Important Considerations: Using IR filters on standard cameras demands patience due to long exposures. A tripod is essential. Furthermore, not all lenses perform well; some can produce a central bright spot known as an ‘IR hotspot’, especially at narrower apertures.

Using Dedicated Infrared Cameras (Conversions)

A more efficient, albeit more committed, approach is to have a digital camera permanently converted for infrared photography. This involves physically removing the internal IR-cut filter from the sensor assembly and usually replacing it with a filter that passes specific infrared wavelengths (like a 720nm or 590nm filter) or a clear glass filter (for full-spectrum capability). Advantages:

• Normal Shutter Speeds: You can shoot handheld in good light, just like a regular camera.
• Accurate Focusing: The autofocus system works correctly (though live view focus is still often preferred for critical sharpness). You see the IR image directly through the viewfinder (DSLR) or on the LCD/EVF (mirrorless).
• Convenience: No need for dark external filters, making the shooting process much faster and more intuitive.

Disadvantages:

• Cost: Professional conversion services cost money, plus you need a dedicated camera body.
• Permanence: The camera is typically dedicated solely to IR (unless it’s a full-spectrum conversion, which offers flexibility but requires external filters for different effects).

Full-Spectrum Conversions: A popular option is converting a camera to ‘full spectrum’. The internal hot mirror is replaced with clear glass, making the sensor sensitive to UV, visible, and IR light simultaneously. This offers maximum flexibility, allowing you to use different screw-on filters (IR-pass, UV-pass, even standard visible light filters) to capture various types of images with a single camera body.

Shooting Techniques and Considerations

Regardless of the method, successful IR photography involves specific considerations: Subject Choice: Landscapes are classic IR subjects. Deciduous trees, grass, and foliage reflect IR light strongly, rendering them bright white or silvery – this is known as the ‘Wood Effect’. Skies, especially clear blue skies with defined clouds, tend to go very dark, creating dramatic contrast. Water absorbs IR light, appearing dark and adding to the scene’s contrast. Architecture can also look striking, revealing textures in a unique way. Portraits are possible but can look unusual; skin often takes on a very smooth, milky appearance, and eyes can look dark and mysterious. Lighting is Key: Infrared radiation is abundant in bright sunlight. Overcast days yield much flatter, less dramatic results. The middle of the day, often harsh for visible light photography, can be excellent for IR. Foliage reflects IR most strongly when it’s actively photosynthesizing. Focusing Revisited: Even with converted cameras, achieving critical sharpness is paramount. Use live view magnification for precise manual focusing or rely on the camera’s live view autofocus. If using an older lens with an IR index mark on an unconverted camera with an IR filter, stop down the aperture (e.g., f/8 or f/11) to increase depth of field, which can help compensate for minor focus inaccuracies. Exposure and White Balance: Your camera’s light meter may be fooled by the unusual light, so check your histogram and consider bracketing exposures. Shooting in RAW format is highly recommended as it provides maximum flexibility in post-processing. Setting a custom white balance in-camera is crucial for previewing the image somewhat correctly and for easier processing later. Aim your camera at green grass or foliage under sunlight and use that as your white balance reference. The resulting image preview will likely look strange (often sepia-toned or with odd color casts), but this is normal.

The Magic of Post-Processing

The raw files from an IR camera, especially one set with a custom white balance off foliage, often look predominantly red or magenta. Post-processing is where the magic truly happens and the distinctive IR looks are created.

White Balance Adjustment

Even if set in-camera, the white balance usually needs significant adjustment in your RAW editor (like Lightroom, Camera Raw, Capture One). You can use the white balance dropper tool on something that should be white or neutral gray in the IR spectrum (like the white foliage) or manually adjust the temperature and tint sliders until you achieve a starting point you like.

Channel Swapping for False Color

This is the cornerstone technique for achieving the popular look with blue skies and white foliage, particularly when using filters like 720nm or 590nm. In software like Adobe Photoshop:

1. Open your processed IR image.
2. Add a ‘Channel Mixer’ adjustment layer.
3. In the Red Output Channel, set Red to 0% and Blue to 100%.
4. In the Blue Output Channel, set Red to 100% and Blue to 0%.
5. Leave the Green Output Channel as Green = 100%.

This swaps the information in the red and blue channels. Since the sky is recorded strongly in the blue channel (due to the custom white balance) and foliage in the red channel (as IR light), swapping them makes the sky blue and the foliage white or yellowish. Further adjustments using Hue/Saturation or other tools can refine the colors.

Verified Fact: The Wood Effect: Healthy deciduous leaves reflect a large amount of near-infrared light due to their internal cell structure (spongy mesophyll layer). This strong reflection is why foliage appears bright white or glowing in typical infrared photographs. Conifers tend to reflect less IR, appearing darker.

Black and White Conversion

Infrared images often convert beautifully to monochrome. The inherent high contrast between sky and foliage, the unique tonal rendering of surfaces, and the ethereal glow lend themselves perfectly to dramatic black and white processing. You have extensive control over the final look by adjusting the different color channel sliders during the B&W conversion process in your editing software.

Creative Exploration

Don’t limit yourself to just channel swaps or standard B&W. Experiment with different color grading techniques, split toning, and contrast adjustments. The unusual color information captured in IR files provides fertile ground for artistic interpretation. Using filters like the 590nm allows for even more color variation, sometimes yielding golden yellows, vibrant cyans, or deep oranges depending on the processing.

The Unique Aesthetic of IR

What draws photographers to infrared? It’s the ability to show the world differently. The Wood Effect turns summer scenes into snowy wonderlands. Skies become deeply dramatic, sometimes almost black. Haze is often cut through effectively, revealing distant details obscured in visible light. Textures on stone and wood can be enhanced. The overall effect is often described as ethereal, otherworldly, or dreamlike. It transforms the mundane into something extraordinary, challenging our perception of reality.

Getting Started

If you’re intrigued, try starting with an affordable 720nm screw-on filter for your existing camera, provided you have a tripod and patience for long exposures and manual focusing. Check online resources for lens compatibility regarding IR hotspots. If you find yourself captivated by the process and results, investing in a dedicated IR camera conversion (perhaps using an older DSLR or mirrorless body you no longer use frequently) unlocks a much more fluid and versatile shooting experience. Infrared photography is a journey into the unseen, offering endless creative possibilities for those willing to explore beyond the visible spectrum.