Tutorial: Infrared Photography

No, this isn’t some sort of spy stuff. You’re simply putting a filter over the lens (or sensor) that only lets infrared light through. It can give photos an otherworldly, fantasy-like effect…

 

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You can see how foliage glows white in infrared shots and how important contrasting items are, such as the old truck here. The sky can also offer good contrast if it is blue; it will turn out quite dark. Here the sky was cloudy but still maintained some interest and contrast.

 

Infrared light is just outside of the normal light/colour spectrum that we can see with our eyes. The wavelengths are a bit longer than the usual colour palette, while on the other side of the spectrum you have ultraviolet, which you can also photograph with different techniques/equipment.

Some of the best subjects are foliage, which turns white, and contrasting items which will be dark, such as tree branches, old cars (as seen above), and even the sky. You’ll learn as you go how things will turn out, but generally foliage is good, with some contrasting elements, and a blue sky.

Filter vs. conversion

The filter is quite dark, so if you are shooting with a screw on filter on the end of your lens you’ll have to compose prior to putting it on. However, live view (using the screen instead of the eyepiece) may help get around this. There is an infrared blocking filter over your sensor; some brands have stronger ones than other brands, so if you are using a screw on filter your exposures will be long, because the camera is blocking the IR light at the same time.

 

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An early IR shot taken with a filter screwed on to the end of my lens, this makes the exposure quite long, as can be seen in the cloud movement, because there is an infrared blocking filter covering the sensor.

 

To get around this you can get an infrared “converted” camera. When this is done, they remove the infrared blocking filter from the sensor and replace it with an infrared filter instead, similar to what you would have been putting on your lens prior to converting the camera. This allows you to compose without a dark filter over the lens, and also gives you much faster shutter speeds. Good companies for this are Lifepixel (which I have used and had a great experience) and Kolarivision (I have not used but heard good things). Local camera repair places may do this as well. There’s one here in my hometown that said I must get the part, and that they would remove the IR blocking filter and install the IR filter.

But now I’m thinking that with mirrorless I could have just gotten the IR blocking filter taken off and gone back to using a screw on filter; it would have probably been cheaper than shipping it off to Lifepixel.

When converting to IR, you may have choices of which wavelength you want it converted to, or “how strong” the IR effect will be. Basically… 720nm (nanometers) is the average, and you can get a lower number conversion which will keep more colour in the scene, or you can get a higher number conversion that will keep no colour at all. Having some colour is nice so that you can do a “colour-swap” and have a blue sky (more on that below). There’s a good example of the differences here: https://www.lifepixel.com/infrared-filters-choices

Focusing

Something to keep in mind is that infrared light is a different length than regular light, so focusing is a bit inaccurate. If you are converting an SLR camera, the company doing the conversion may calibrate a lens for you, or you will have to use manual focus on the lens and focus a bit closer than normal. If you’re doing this it’s recommended that you use a small aperture, around f11, to have better luck with achieving focus. Most cameras have a live view option, using the screen instead of the eyepiece/viewfinder, and you can autofocus or manually focus that way because it is a direct feed from the sensor and what you see is what you get. This issue can be avoided if you have a mirror-less camera since they do their focusing based on the sensor anyway. Mirror-less is becoming popular for infrared photography because of this.

 

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Just another IR photo to break up the text a bit.

 

White Balance and Hot spots

Sometimes you may get a “hot spot” in the centre of the photo. I’m not 100% sure about what is happening with the light inside the lens, suffice it to say I know that it is usually lens dependent; you’ll get the spot with some lenses but not with others. It can be a pain to get rid of. Lifepixel is compiling a list of lenses with this issue but it doesn’t seem very complete yet.

With auto white balance you’ll usually get a very red photo like the one below of the truck. You can either do a custom white balance with your camera (check the manual) or you can shoot RAW and use the eye dropper tool in Lightroom (or something similar in a different program) to select an area of the scene you want to be the guide for the white balance of the image. If you do a custom white balance in the camera, it’s usually good enough for most situations; you don’t have to do it every time you’re at a different place.

 

Aug28_2006 024-edit
One of my early infrared images. You can see the “hot spot” in the middle of the image. Also, this is a good example of what it will look like if you don’t do a custom white balance prior to shooting. But, not to worry…
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…You can use the eyedropper tool in Lightroom to get a proper white balance simply by clicking on the grass or trees.
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And here is the final photo after some painstaking work to remove the hot spot. Lightroom’s circular gradient tool might be useful for this, I haven’t tried it yet.

 

Colour Channel Swapping

As you can probably tell already, I like the blue sky effect in IR images. It’s quite simple to do this, but you need to have access to a program that allows you to access the colour channels individually, such as Photoshop. If you don’t have Photoshop, you can download a free copy of the older Photoshop 2 from Adobe’s website (at least you could when I did it a few years ago). All you do is:

Go into the Red channel – Turn the red to 0 and the blue to 100

Go into the Blue channel – Turn the blue to 0 and the red to 100

This effectively does the “colour-swap” and you can create an action in Photoshop to do this with a single click of the mouse. I’ve included a before and after example below:

 

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A custom white balance shot.
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The same photo after a colour channel swap.

 

So that’s it. Feel free to email me at theburntpixel@yahoo.ca if you have any questions.

 

Here are a few more sample photos:

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Aug3_2015_XS_0251-edit-edit-edit

 

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