False Color Infrared Photography
Published in Digital Photographer Philippines Issue 20: Coast to Coast
(Updated 6 November 2008)

With the onset of digital imaging and camera sensors sensitive to the near-infrared wavelengths, capturing infrared images have never been easier and more convenient.

In the 1960's, Kodak introduced the Ektachrome Infrared Aero Film Type 8443 which gained popularity for being able to capture colored infrared images. Combined with the effects of infrared and the unusual colors produced, it introduced something unique to the world of photography.

Today, the need for expensive and usually scarce special films and emulsions are gone. One can simply attach an appropriate filter to their digital camera or have their camera serviced to modify the sensor's low-pass filter to shoot dedicated infrared wavelengths all the time. Along with the capabilities of editing software such as Photoshop and that no standard method of processing has been set, the possibilities have become endless. However, there are still methods that produce aesthetically pleasing results more than others and this tutorial will deal with one of those methods. But before anything else, shooting and "seeing" digital infrared isn't as straight forward as it might seem.

Visualizing Infrared Light
Yes, infrared photography has this effect to it that makes the image look unique and special. Along with the premise of capturing light that is beyond what we see or that is invisible, it has attracted a lot of enthusiasts and experimenters. This does make it easy to forget the basics especially the first time producing something significantly different and surreal from the usual visible light captures. But with all these special effects, they won't automatically turn your ordinary image into something stunning. A mediocre image is still a mediocre image even with infrared effects. Thus, it is imperative to remember the principles of capturing a great image and not just imagining every single piece of foliage turn to white. Here are a few pointers on how to visualize and capture infrared light properly:

Choose a good subject and composition. There are certain subjects which work better with infrared than others as it affects some things differently. Along with foliage turning to a white or yellow hue, the skies darken; water reflectance increases especially with still water surfaces; and human skin turns pale white just to name a few. And as with all fields of photography, proper composition of all elements is essential.

Take into account the light. Infrared photography works best with direct sunlight as solar infrared radiation is the biggest source of light available for any infrared scene. More often than not, erratic lighting will make for unpleasant results especially for false colors and overcast skies with diffused light will produce dull, low contrast images. This can also cause skies to burn out and leave ground subjects underexposed. Graduated neutral density filters won't be of much help either as they are not designed to block infrared light.

Compress time. Learning to see and compress long exposures into a single frame will give an advantage over standard images. The effect will be similar to using extreme neutral density filters making for dynamic images with streaking clouds, blurred motion, and misty or glass like effects on water depending on its movement. This applies mostly to infrared photography using add-on filters because modified cameras normally have just about the same exposure time as an unfiltered camera. This also depends on the camera used. There are some models even if unmodified, can capture infrared images in short handheld exposure times. And there are those which need long exposures to produce an image, some of which can take as much as over 15 stops longer than normal.

Shoot it right. Get the proper white balance every time you shoot. Use a custom white balance taken from the surrounding foliage with the filter attached. There may be some other ways of getting the proper white balance for your specific camera which you can try to search the internet for or better yet, experiment on getting it yourself.

Always shoot RAW. It is critical to get the proper white balance because it not only affects the colors but also the exposure of the image. And with RAW, there is some leeway for readjusting white balance using the white balance picker tool in your RAW editor which cannot be done with JPEG captures. But getting the correct white balance during the shoot itself should be a priority.

Compose your image, attach the filter, and then refocus your lens. The wavelength of infrared and visible light is not the same; as a result, there will be a focus shift if you pre-focus without the filter attached. Despite not being able to see through the filter and viewfinder, the camera will still be able to autofocus. Use a sturdy tripod and your camera's mirror up feature to get sharper images. When doing long exposures, remember to use a viewfinder cap to prevent stray light from leaking onto the exposure.

The final part is how you process your captures. The following is just one way on how to go about trying to make sense of the psychedelic colors; turning your great image to something potentially spectacular.

1 Converting RAW Files
First things first, any Adobe image processing software should be avoided when converting your RAW files as they force their own tone curve which significantly alters the white balance (Lack of below 2000 Kelvin temperatures) and exposure of the output image from that of the one captured by the camera. This includes Adobe Camera Raw as seen below.  (Update: You can use DNG Profile Editor from Adobe Labs... thanks to Jay Jallorina for the info.)

Luckily, there are free RAW converters out there that you can download and use to convert your RAW files to TIFF images which we will process later on. We recommend using RAWTherapee or SilkyPix which does not alter the white balance.

For Pentax K10D Users: This wasn’t included in the article. It’s sort of a cheat to get the same colors in ACR by editing the camera profile at the expense of increased color noise or posterization.

2 Editing in Photoshop
After converting your RAW file to TIFF, load it into Photoshop. First, examine the histogram for any exposure corrections to be made. Always use the colors channel mode for the histogram to preview the RGB and Luminosity channels.

3 Curves Adjustment
Next thing to do is add a Curves Adjustment Layer by clicking on the adjustment layers button at the bottom layers palette.

Once the dialog box is open press the Auto button to automatically correct for the color and exposure curves. Once done, you can add a slight S-curve adjustment to enhance contrast at the same time.

4 Masking Highlights
Look at the histogram again for highlight clipping that may have resulted from our curves adjustment. Select the Layer mask icon at the right of the curves adjustment layer’s icon. Use an appropriate brush opacity to mask out the highlights.

5 Color Inversion
Now comes the part of realizing the false colors of the image. There are a few ways of doing this like the popular Red and Blue channel swap method and the Color Inversion method. For this article, we shall use the less known color inversion.

Just like the curves adjustment before, add another Invert adjustment layer.

6 Change Blending Mode
Change the adjustment layer’s blending mode to color to overlay that color over the image. This changes the sky colors back to the bluish hue we are familiar with.

7 Back to the Histogram
Checking the histogram again, you may be faced to contend with some color casts. This image needs some adjusting for the blue cast present indicated by the histogram.

Add another curves adjustment layer and select the blue channel to reduce the blue cast.

8 Final Adjustments
Adjust saturation and contrast to your liking and add sharpening.

9 Final Word
Creating stunning infrared images isn’t limited to processing them. Going back to the basics and choosing the proper subjects, composition and taking into account the light and proper white balance during the shoot is essential to the whole process.

Finally, no method is the “be all and end all” of infrared processing. Also, every camera is not created equal for false color infrared. There are cameras that produce a lot of false colors out of the box and there are others that barely do especially with infrared filters. Just like one processing method may work for one camera, but may not for others. The key is to experiment and make the image into your own.

This is a repost from DPP since my image host is going bonkers right now.

An IR filter is a nearly opaque glass filter which filters out nearly all visible light and lets through a certain wavelength of Infrared light.

For example, the Hoya R72 Infrared filter will let through anything above 720nm in wavelength. Anything under that rating, won't reach the sensor. In relation, visible light, or the light that we can see is at a wavelength of 400nm - 700nm. Below or above that is invisible to us. So infrared photography is just like photographing the invisible.

Anything that is reflecting or emitting a high amount of infrared will be white in an infrared exposure. The lower the IR the darker the image will be. IR does not generally work at night, indoors, nor in deep shadow as there is no Solar IR present. Though an electric coil stove does emit IR hehe. A bright sunlit scene is best for IR photography.

Requirements for filter based Infrared Photography:

1. Always use RAW. JPEG isn't as favorable in adjusting white balance.
2. Use a tripod, mirror-up and a cable release. Long exposures tend not to be sharp especially in windy conditions. Some cameras do permit handheld IR like the Pentax K100D and Nikon D40, but using a tripod is better  because you can use the lowest ISO since high ISO's at long exposures introduces a lot of noise and hotpixels (I don't use in-camera noise reduction). Or atleast the highest ISO with an acceptable noise output if you're in a hurry.
3. For colored infrared photography: There is a strict white balance requirement. A custom white balance on something sunlit green is your target here. Avoid dark greenish and shadowed grass. A big yellow-green leaf is recommended like a banana tree's leaf.
4. For Black & White Infrared: The above will work but a Tungsten white balance preset will do well too since it will output a reddish image but not as red as Auto White Balance. Just apply a Black & White adjustment layer with a blue, green, or red filter (or whatever works) in Photoshop and you're done.
5. If your camera takes super long exposures for IR. Use the viewfinder cap! Light can leak through the viewfinder especially with Pentaprism based cameras causing colored streaks to show up in your images.
6. After composing your shot. Try to focus manually before putting the IR filter and take an image with the IR filter on. Then try focusing with the IR filter on. Some lenses with the IR filter on causes a big focus shift. So test out which one is better for you. Using the hyperfocal point of your lens is also recommended.

Disclaimer: I cannot guarantee that this workflow will work as stated with other brands and models except for the Pentax K10D and the Hoya R72 IR filter. Different cameras and models have different exposure times. Though, the Pentax K10D has a similar (loooooooong) exposure time with the Nikon D80 (as tested with Jetty Remigios' D80) and I assume the same goes with Sony A100 and Nikon D40x since they all use the same 10mp Sony CCD sensor. The Pentax K100D and the Nikon D40 also use the same 6mp Sony sensor and they also seem to have similar exposure times for IR capable of handheld shooting. I haven't used the Cokin yet so I can't be sure of the output too.

Here is the workflow I did for the AWM Tree:

Shot #1

Shot #2



By the way, with long exposure IR cameras like the K10D and D80, you have to place the viewfinder cap to avoid light leaks coming from the viewfinder. I didn't know this at the time and as you can see, there are horizontal color banding in the above pictures.

Now for the Wawa and La Mesa IRs, this is the workflow I used on all of them:

As you can see from my images, I generally go for the peachy colored trees instead of pure white ones to get a difference in contrast with the clouds and skies. If you want whiter plants, just adjust or add a Hue/Saturation adjustment layer and make change the Reds to a 0% saturation. Or use Selective Color. You can also adjust the saturation in ACR beforehand.

I hope someone finds this helpful. Thank you for reading!

Here are some resources for other IR workflows:
http://dpfwiw.com/ir.htm
http://www.lifepixel.com/digital-infrared/digital-infrared-photography-instructions.html
http://www.lifepixel.com/videos/basic-infrared-photoshop-info.html
http://www.xdeltax.com/infrared/index.html
http://www.wmphotos.com/Links/8a-Nikon%20D100.htm
http://www.naturfotograf.com/UV_IR_rev00.html

PS. Please forgive the grammatical errors above, editing, resaving and reuploading the images is quite cumbersome. :[