If you haven’t heard the term “IR Pollution” then you’ve either seen it and didn’t know what was happening, or you’ve been lucky enough to avoid it because of the camera you have. So let’s get the avoiding IR Pollution out of the way. If you have a camera like a canon DSLRs, you might not have seen IR Pollution because those cameras include an internal Optical Low Pass Filter or “OLPF” with an IR-Cut filter.
Check your camera specs to see if it includes OLPF. If not, then you should pay close attention to the words that are coming out of my mouth, or from my fingers.
Cameras like the RED Scarlet, Epic, and Blackmagic Mini Ursa, are vulnerable to IR pollution.
Put simply, Infrared Pollution happens when you put on heavy neutral density filter, and your footage turns redish, looks brownish, and your pride as a cinematographer is crushed. In the beginning that happened to me a lot, and I was wondering what I was doing wrong. So here is the explanation. A camera image sensor records light. Not only the visible light, like the colors we see around us, but also a tiny bit of the infrared spectrum that we don’t see. The infrared light mixes with the other colors in your image and the end result is IR Pollution. Your blacks turn red and color correction can’t save you this time.
The solution is simple: use a ND filter that has a built-in IR block. I actually have a Tiffen variable ND filter and I got a B+W IR Cut Filter and I stack the two together.
Every type of camera reacts differently to each of these filters so you need to test your camera with different IR filters to find what works best for you. Also note that lenses can alter the colors as well so keep that in mind.
Here is a video I did quickly explaining what IR Pollution does to your image:
Notice the image on the right has the IR Cut filter on and her t-shirt stays black, while the t-shirt on the left turns red.
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