Infrared photography is the gateway into the hidden world. It shows you what your eyes can’t see.
What is Infrared?
Human eyes are not capable of seeing everything. There are many worlds hidden from our eyes. The visible light spectrum for the human eye is typically between 380 to 700 nanometers (in terms of wavelength).
Anything below or above this bracket of wavelengths is hidden from us despite being there. Infrared light, commonly referred to as thermal radiation, is the band in the electromagnetic radiation spectrum with wavelengths above red visible light between 780 nm and 1 mm. Unlike our eyes, films and camera sensors are sensitive to Infrared light. Usually, the wavelengths from 700-900 nm are used in photography.
Infrared photography refers to shooting with film or a sensor that is sensitive to infrared light. The spectrum used in infrared photography is near-infrared to distinguish it from far-infrared. Near-infrared is the spectrum closest to the wavelengths visible to human eyes.
The longer and far-infrared rays are involved, it becomes far infrared. Far infrared is closer to the microwaves region.
Infrared Passing Filter
Not all cameras are capable of shooting infrared light. Generally, the film used is sensitive to visible light. That is why an infrared passing filter <- Affiliate link 🙂 is used for this niche of photography. This filter lets the infrared light pass through the camera while blocking most of the visible lights.
The infrared filters look black or deep red.
The filter that blocks the infrared light and passes other visible lights is also called an infrared filter. Many people confuse this filter with an infrared passing filter, but both of these have totally contrasting features.
These filters are commonly used in Astrophotography or Night Light Photography.
History of Infrared Photography
There is no history of the practice of infrared photography in the era of black and white photography. Until the 20th century, infrared photography was not under the act. The first infrared photo was published in 1910 in the century magazine.
American physicist Robert William Wood is credited as the father of infrared photography. It was part of his work in the field of optical physics. Initially, he devised a filter named Wood’s Glass which limited the regular light rays but allowed UV rays and infrared rays to pass. His first work was taking infrared landscapes in 1911.
People and photographers across the globe started paying attention to infrared photography when it proved to be very valuable during WWI. The developmental era for this niche was in the 30s and 40s when multiple infrared-sensitive films were invented. By 1937, 33 kinds of infrared film were introduced from 5 companies, including Kodak, Agfa, and Ilford.
At the same time, this work also started appearing in Hollywood, boosting its popularity. With that, after the world wars, military usage of infrared photography also increased. With passing years law enforcement agencies, forensics, different fields of sciences, and artists also adopted it. Today, it is a crucial part of hundreds of fields. (Refer to application/uses section for details)
How to know if your DSLR can capture IR light?
You can check your DSLR compatibility for infrared light via a simple test. Take a picture of a TV remote control pointed at the camera in a darkened room. Depress any button on the remote while taking a picture. If you see a spot of light in your image, your camera is sensitive. If not, your DSLR cannot shoot beyond the range of 700 nm, and you need an Infrared passing filter.
Even if your camera is IR light sensitive, we still recommend using an IR passing filter for better results. <- Affiliate link 🙂
Dedicated camera for Infrared Photography
If you have a traditional camera, it can be converted into an infrared-sensitive DSLR. The method of conversion is inexpensive, but we strongly recommend this with your backup camera. Do not attempt any experimentation with your primary camera; instead, use an infrared pass filter.
There are few options for converting a DSLR into an IR camera too. You can make a camera only receive infrared light by replacing the IR blocking filter in the camera sensor with a filter that instead blocks the visible light. The camera can also be converted into a full spectrum camera which allows all ultraviolet, infrared, and visible wavelengths.
It can also be converted into a two-spectrum camera which allows infrared and visible light. These two options involve removing the infrared filter and replacing it with a similarly-sized sheet of clear glass or a UV blocking filter. The new spectrum of the camera will depend upon the new filter you screwed in front of the camera center.
If you want to go for this conversion, though there are several DIY videos and articles available online, we recommend you take your camera to some professional. The conversion can be costly but still cost you less than buying an actual infrared camera and will also give better results than using removable filters.
Applications/Uses of Infrared Photography
There are so many advancements in the world for which Infrared Photography truly deserves the credits. You might assume that this is not a very popular genre of photography because you won’t see it commonly on your social media feeds but truly, it is everywhere. Some fields where there is extensive use of IR photography are:
- Medicine: IR light can easily penetrate through human skin making it easy for doctors to spot subcutaneous problems. Some common uses in medicines are in dental, determining the severity of burns, detecting tumors, acute abdomen, and peripheral nerves diseases detection.
- Forensic sciences: use of IR photography is a day-to-day part of the life of a forensic scientist. Infrared Photography shows them things invisible to human eyes. These IR photographs are commonly used as proof against culprits in a court of law.
- Astronomy: Astronomical developments couldn’t be possible without infrared cameras as mostly celestial objects are not visible to human eyes.
- Military: From target acquisition to use in military helicopters to detect illegal drugs growers, the military also uses IR photography.
- Ecology: To develop accurate maps of the area’s shorelines and drainage patterns, find active plant areas and algae concentration, and distinguish animals from the vegetation that they inhabit in the wild.
- Art: Infrared photography is a non-destructive technique in art used by conservators. They use it to examine paintings and artworks and detect hidden details under the upper layers, such as added paint, underdrawings, and hidden signatures or watermarks, without any damage to the artwork.
- Security and Law Enforcement: Infrared cameras can capture in complete darkness, which makes them perfect for surveillance purposes.
Processing IR Images
The raw images viewed from the camera are dull, pinkish, and lack in contrast. Don’t worry about this; it is completely normal for infrared photographs as these images have a higher temperature than photographs of the visible spectrum. This is due to the DSLR sensor, and the IR filter installed.
The most common and effective way to process your IR images is in post-processing through Adobe Photoshop light-room. Adjust and balance the white light in your image. The temperature should be set to 2100 with a tiny of -72.
You can then move the image to Adobe Photoshop CS5 to adjust the colors and give your image a mixture of blue and yellow.
What lens to use?
Where it is a generally accepted concept that the quality of the image depends upon the quality of the lens, in the world of IR, the best lens does not have to produce the best results. That’s true; in IR photography, the low-cost lenses may produce better images than the best ones.
Which camera lens will work best for your infrared photography depends upon the results you are looking for. Going through the specifications of DSLR,/mirrorless, or /point and shoot cameras, will help you find the camera which is the perfect fit for you.
Infrared photography enables the photographers to explore a new world. Sometimes these results can leave you in awe. It truly helps you to step into unseen worlds. The outcome of IR photography looks extremely different than what we see with our eyes.
Exploring the world with an infrared-sensitive camera, you will find everything around us, textures, colors, leaves, plants, and even humans can reflect infrared light in unique ways.
IR photography opens up thrilling new worlds for photographers to explore, considering the flexibility IR converted DSLRs provide. This article is merely an introduction to this genre of photography. Just get an infrared passing filter <- Affiliate link 🙂 and explore this niche, and the results will advocate for themselves.