What is the difference between an infrared filter and an ND filter? I have a big stopper and I would like to take some images to show the infrared spectrum I have seen images where green foliage shows up red and any heat source shown up white §Is there any lens filter recommended for this genre of photography


1 Answer 1


ND stands for "neutral density" - it is a filter type that (in theory) absorbs all wavelengths of the visible light by the same amount.

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Effect of a ND-filter. CC-BY-SA 2.0: Robert Emperley

IR filters filter out all but certain wavelengths - the (near) IR wavelength of the filter. So basically, they are IR-pass filters, not IR-block filters. Thanks @TheLuckless!

As @Hueco states in his comment, IR filters will cut everything below a certain value. That value might be between 650 and 720nm - visible light, however, does go up to 750nm. Thanks for clarifying that, Hueco!

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Typical result of using an IR filter. Some effort was put into post-production: The red and blue channels were swapped. CC-BY-SA 2.0: Jannis

What you think of (white heat source, everything else red-ish) is most probably a thermographic camera - they differ from regular cameras in a lot of ways, including lenses that are (typically) made out of Germanium.

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Thermographic image. CC-BY-SA 3.0: Lutz Weidner

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    It's important to note that most IR filters block somewhere between 650nm and 720nm and below. Important because visible light goes up to ~750nm.
    – OnBreak.
    Apr 5, 2019 at 21:50
  • @Hueco Is there something you do not know better than me? :D In all seriousness, though: Will include that ASAP - just looking for some CC-BY-SA sample pictures for the respective categories.
    – flolilo
    Apr 5, 2019 at 21:52
  • lol. I just happened to start looking at getting a camera converted by the folks at life pixel (many hours spent researching this topic). I'm just not sure if I want to send in the 60D or get a cheap used Rebel for the job. I do love my film, but when it comes to IR shooting, digital wins hands down
    – OnBreak.
    Apr 5, 2019 at 21:56
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    @TheLuckless Hopefully I integrated the information from your comment so that this is more clear now - thanks for the tip!
    – flolilo
    Apr 5, 2019 at 22:20
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    @flolilo – OVF is useless with IR. When I had an IR-converted Rebel, there was no consistent exposure compensation that would work. Autofocus didn't work. Had to use Live View and manual focus to get reasonable results. Mirrorless with LCD or EVF would work better.
    – xiota
    Apr 6, 2019 at 6:22

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