Infrared photography (hereinafter referred to as IR) allows you to capture light reflected in the infrared range on a photo. Any photography captures reflected light. But in the case of infrared photography, we are talking about the range invisible to the eyes.
The visible light spectrum includes a range of light wavelengths from approximately 400nm to 700nm.
At the same time, it is necessary to clarify that such a photograph does not reflect how warm or cold individual objects are - this requires more specific devices, camera matrices are not capable of this.
Infrared photography captures near-infrared light in the ~ 720 nanometer region. In fact, this light is on the verge of what we can see with our own eyes. For comparison, night vision thermal imagers shoot in the range of 8000-15000 nanometers. This is the far infrared range.
We will work in near-infrared radiation from 700 nm to 1400 nm.
With the theory sorted out, it's time to practice.
How to get infrared photography?
To ensure that only the infrared spectrum is visible in the photo, it is necessary to cut off all other light radiation. For this, special light filters are used.
One of the most recommended and popular is Hoya R72 Infrared... The filter cuts off about 11 stops of light (which roughly corresponds to ND1000).
If you use different lenses, I recommend taking a larger diameter filter and purchasing adapter ring set.
Hoya R72 blocks about 95% of the light entering the sensor. As a result, you only capture the waves in the area. 760-860 nanometers, as written on the back of the filter box.
In the source, this picture looks very red. At the same time, shutter speeds for such a photo will be so long that you cannot do without a tripod. No stabilization (what is optical, what matrix) will not allow you to comfortably shoot at shutter speeds of 1 to 15 seconds. I shot in this range of shutter speeds. The specific value depends on the value aperture.
Another nuance - you need to shoot in bright sunny weather and in summer. In the evening, there will be no effect, and in winter too. Your task is to capture the maximum possible light. And even on a summer July day at noon, you will be shooting with a tripod with a long exposure. This is how this filter works.
The next nuance is focusing. The fact is that the focus point is different in the visible range and in the infrared spectrum.
How to focus for infrared photography?
Autofocus will not work with this shade. You will need to focus in manual mode.
It all depends on your camera and lens. If you have a DSLR, you need to switch to life-view mode, otherwise it won't work at all. You don't need to switch on a mirrorless camera.
Next, it is worth opening the lens aperture to the maximum. If you are shooting in semi-auto exposure mode, the camera should adjust to the filter and you will see a noisy red image. Next, you need to turn on the digital zoom and try to focus where you need it. This process is not easy, because visibility will be poor and the picture will be very noisy. When you focus, you need to close the aperture for more depth of field.
As for the lens, if you have a distance scale lens, then you're in luck. Many of these lens models (but not all) have a separate index for the infrared focus point at infinity. For example, in lenses Canon EF 50mm f1.2L и Canon EF 16-35mm f2.8L III such a label is present, and in EF 135mm f2L it is not.
If you shoot with a wide-angle lens, focusing will be easier due to the greater depth of field. That is, even if you miss a little, you will have some head start in getting into the grip. But with standard and telephoto lenses, getting into focus can be problematic.
Regarding detail, keep in mind that the greenery in the frame will often be indistinct. you shoot at long exposures, and the leaves tend to sway in the wind.
How do I process IR photos?
After you get at least a sharp image, you need to color-process it.
Remember that we only shoot in RAW format. JPG will be left to phones and action cameras. The color correction that we are facing is unthinkable without the RAW format.
The first thing we do is open the photo in Lightroom or CaptureOne or AdobeCameraRaw, where we need to set the white balance to a minimum.
With this, we say goodbye to Lightroom and go to Photoshop. When exporting from Lightroom, set the tiff / 16 bit format per channel.
Next, in Photoshop we need a tool channel mixer... In it you need to register the following settings:
- First option
In the red channel - red 0, green 0, blue 100
In the green channel - red 0, green 100, blue 0
In the blue channel - red 100, green 0, blue 0.
- The second option
In the red channel - red 0, green 0, blue 100
In the green channel - red 0, green 0, blue 100
In the blue channel - red 100, green 100, blue -100
You can manually adjust the channels to your liking (you can do this for a long time :).
Next, you need to add contrast to the resulting image. This can be done using curves. My curve settings:
That's all, the details depend on your creativity.
The goal you go to with color grading is to get white in the foliage, but everyone has their own taste, you can play a lot here.
Here's what I ended up with:
There are many styles of processing such photos with different color accents. More examples of IR photography can be seen in the video at the end of the article.
IR photography Is a great way to push the boundaries of your creativity and get interesting shots that sometimes look like shots of otherworldly reality. I personally have associations with the layers of the Twilight from Lukyanenko's Patrols. I would visualize them like this. But remember that this whole thing works well in the summer, when solar activity is at its maximum.
Below is a combination of infrared photography with processing (top part) and ordinary photography (Bottom part).
And once again, a link to the filter that opens access to the lower layers of the Twilight - Hoya R72 Infrared.
A video where I talk in detail about everything: