Up for Discussion – Infrared Photography
Last week for the Monochrome Madness Challenge I did an image and I added a infrared filter in post to it to give the impression of it being infrared. It was fairly obvious it wasn’t, but it was fun playing around with it. Infrared is something you do see from time to time, but not many of us have dedicated equipment for it. I thought it might be good to get some information on how you can go about doing it, so I have asked fellow blogger, Infraredrobert to guest post and to tell you how he does his.
Infrared Photography by Robert
By revealing what is normally invisible to the human eye, infrared photography captures light in the near-infrared portion of the electromagnetic spectrum by recording infrared reflections on either specially sensitized film or digital camera sensors.
It’s all Just Radiation: The Science Behind the Art
Before we get to the art of infrared (IR) photography, I need to speak briefly about the science behind it. As photographers, we are doing nothing more than capturing visible light radiation that is reflected off our subjects. Visible light is just a small portion of the electromagnetic spectrum that our unaided eyes can detect. The human eye can see light waves with frequencies between 390 to 700 nanometers (1 nm = 1 billionth of a meter). Infrared light lies just beyond what the human eye can detect, with frequencies between 750nm and 1mm. In the digital infrared photography discussed here, we will be imaging in the near-IR portion of the spectrum at wavelengths between 700nm to 1400nm.
The important thing to note here is that digital infrared photography captures reflected light radiation – not emitted radiation. Therefore, you cannot “see” in total darkness using near-infrared imaging.
Camera and Equipment
Digital camera sensors (CCD or CMOS) do nothing more than convert light into a digital value. Camera manufacturers have known for some time that these sensors can detect light outside the visible spectrum, so they provide a dichroic filter (hot mirror) over the sensor to exclude unwanted (IR) light. As camera technology has evolved, these hot mirrors have become better at excluding unwanted light from the sensor.
If you would like to try shooting digital infrared, you have two options: Find an older camera with a less efficient hot mirror (such as the Nikon CoolPix 950) and use a filter over the lens to exclude visible light (such as a Wratten 87 or Hoya RM-72); or convert a camera into a dedicated IR camera by replacing the hot mirror with one that passes only IR wavelengths. It is important to note that once a conversion is done, you can no longer take conventional images with the camera.
For my imaging, I have opted for the latter and use a converted Nikon D100. My camera was converted by lifepixel, but there are numerous companies worldwide that perform this service. My only recommendations are to use a reputable company, and do not attempt the conversion on your own.
Another important consideration is the lens you will use as some are better than others for IR imaging. From my own experience, my standard 18-55mm Nikkor yields the best results, while images from my much more expensive 12-24mm Nikkor are disappointing due to a lot of internal flare from the optical elements. Check around for online feedback for your particular lens to see if others have had any issues with them when shooting infrared.
How I Work
All my shots are taken in aperture priority mode using a three-frame bracket of +1, 0, -1 stops. Capture is done in RAW mode and brought into Photoshop through Adobe Camera Raw (ACR).
After picking the best image from my bracketed set in Adobe Bridge, I increase the Clarity to 75% in ACR (Adobe Camera Raw) and then open in Photoshop (PS). The images will have low contrast and look very red as they are brought into the post-processing program.
1. Channel Mixer: Working with adjustment layers in PS, I do a Channel Swap using the Channel Mixer. Set the Red channel to R=0 G=0 B= 100; set the Blue Channel at R=100 G=0 B=0.
2. Levels adjustment: Sometimes “auto” works, but be aware that this will affect color balance as well, so use with caution. Most images need both a boost the mid-tones and in the contrast.
3. B&W or Color: At this point, you need to decide if you want to have the image retain color, or go as monochrome. When converting to monochrome, I always use the Convert to Black and White adjustment rather than simply converting to grayscale. By choosing the B&W adjustment option, you can further manipulate the contrast by using the color conversion sliders.
4. Tone: The Toning option is done through the Photo Filter adjustment. My particular favorites are Sepia (Warming) and 80A (Cooling). I rarely go much more than 15% with either.
5. Brightness Contrast/Curves: Use either or both to get you to where you want to be in the image.
6. Finalize: Flatten the layers and Smart Sharpen (Amt. 133, Radius 1.5).
Of course, any of these steps can be used with layer masks, blend modes and other elements to bring out what you want in the final image.
On a Personal Note
I am particularly fond of shooting man-made objects juxtaposed with natural elements. In post-processing, the clouds and sky are often a surprise as formations are usually invisible to my eye when framing the shot. Regardless of your subject matter, infrared photography allows you to truly see your world in a different light.
A special thank you to Leanne for allowing me to discuss this topic here as well as hosting all her very informative posts. If you have any additional questions, please feel free to email me at: Robert@digital-infrared.com
www.digital-infrared.com (IR images only)
www.infraredrobert.wordpress.com (IR and Conventional imaging)
http://inadifferentlightbook.wordpress.com/ (Book sample site)
IR lens comparison chart: http://dpanswers.com/content/irphoto_lenses.php
Back to me, I would just like to thank Robert for writing this for us and I hope you learned a lot more about infrared photography. The results are always stunning. He has sent me some more image for you to look at as well, so I will included the ones above as well, and the extra wonderful images.