An infrared high-pass filter blocks light below its rated wavelength and passes everything above it. The number on the filter is its cutoff in nanometers (nm). Visible light ends around 750 nm, so the lower the number, the more visible light gets through and the more color you can get out of the image. The higher the number, the closer you get to pure infrared and a monochrome image.

In practice:

  • 550 nm gives the most vivid color.
  • 590 nm gives strong, saturated color. This is a popular color infrared filter.
  • 665 nm gives a subdued color.
  • 720 nm gives either a lightly saturated color when white-balanced on a neutral subject or white foliage and blue sky when white-balanced on foliage. Also popular for monochrome images.
  • 780 nm gives the faintest blue sky and white foliage. Also good for monochrome.
  • 830 nm and higher pass only infrared light and produce monochrome images. These offer the darkest skies and water.

Buy quality filters from known brands. Cheap filters leak visible light and make images hard to process, especially on unconverted cameras.

Infrared Filters Compared

Filter Light Transmitted Look Camera More
Full spectrum (no filter) Ultraviolet, all visible light, and infrared Red and violet cast; bland on its own Full spectrum conversion What Camera Should You Convert to Infrared?
550 nm Green, yellow, orange, red, and infrared The most vivid color Converted only The Orange Filter, 550 nm
590 nm Orange, red, and infrared Saturated color: a blue sky and yellow or orange foliage after a color swap Converted only  
665 nm Red and infrared Moderate, realistic color that’s easy to push toward vivid or monochrome Converted only 665 nm Infrared Filter
720 nm A sliver of red, and infrared Color or white foliage depending on white balance and a blue sky after a swap, or monochrome Converted, or unconverted with long exposures Kase IR720 Infrared Filter
780 nm The faintest red, and infrared Monochrome, or a pale blue sky after a swap Converted, or unconverted with long exposures 780 nm Infrared Filter
830 nm to 850 nm Infrared only Monochrome with the brightest foliage and dark skies and water Converted, or unconverted with very long exposures Deep Infrared with an Unconverted Camera
Dual-bandpass (IR Chrome, NDVI Blue IR, Super Blue IR) Blue in one band and red/infrared in another Blue sky and red or orange foliage, with no swap Full spectrum only IR Chrome Infrared Filter Review
Candy Pink (stacked film filters) Mostly blue, some green, and infrared A blue or teal sky and pink, red, or magenta foliage, with no swap Full spectrum only Candy Pink Infrared Photography

How High-Pass Filters Work

Visible light runs from about 400 nm (violet) to 750 nm (red). Camera sensors record from about 350 nm to 1000 nm, so every camera has a hot mirror filter in front of the sensor that blocks infrared. There are two ways to get past it:

  • Put a filter on the lens of an unconverted camera. The hot mirror still blocks most of the infrared, so exposures are long. Use a 720 nm or higher filter. A 665 nm or lower filter on an unconverted camera records visible light and no infrared.
  • Convert the camera. The hot mirror is replaced with an infrared filter, such as 590 nm, or with clear glass for full spectrum. Exposures are normal, and you can shoot handheld.

On a converted camera, a lens filter only changes the image if its cutoff is higher than the conversion’s. A 665 nm filter works on a full spectrum or 590 nm camera, but does nothing on a 720 nm camera. Full spectrum, ultraviolet, Dual-Bandpass, and Candy Pink all require a full spectrum camera.

It doesn’t matter whether the filter is inside the camera or on the lens. A 590 nm conversion and a full spectrum camera with a 590 nm lens filter of the same brand produce the same image. See Full Spectrum Plus Filter Compared to Converted to Filter.

Which Filter to Choose

Pick the look you want first, then find it in the table above.

Chapter 3 of my book, Color Doesn’t Exist: A Practical Guide to Infrared Photography, goes further: my filter recommendations for each style, how to start without a big investment, and how to choose between a full spectrum and a filter conversion. You can listen to the recommendations in the audiobook sample.

Color Doesn’t Exist

My own travel camera is a full-spectrum Fujifilm X70 with three lens filters: 665 nm for color, 780 nm for monochrome, and IR Chrome. I use the 665 nm most: it gives color I can make more or less saturated, and it converts well to monochrome. See Infrared Travel Camera Kit.

Kolari Vision Infrared Lens Filter 665 nm Kolari Vision Infrared Lens Filter 780 nm

Not All Filters Are Equal

  • Cheap filters have shallow cutoffs. They let through more visible light than they should, making images hard to process. Use high-quality filters from known brands.
  • The same number can look different between brands. The STC Optics 720 nm filter lets in enough visible light to behave more like a 665 nm. The Kase IR720 review compares it side by side with the Hoya R72.

If you have an unmarked filter or a used converted camera, photograph a rainbow gradient on your monitor and see which colors survive. See Which Infrared Filter Do I Have?

Exposure by Filter

Unconverted cameras need long exposures and a tripod, and exposure time increases with the filter number. At ISO 200 and ƒ/5.6, my unconverted Fujifilm X-E1 needed 0.7 to 3.2 seconds with a 720 nm filter, and about 1 to 3 seconds with a 780 nm filter. Exposures vary widely between cameras: some need 5 to 30 seconds at 720 nm, and filters of 800 nm and higher can take several minutes.

Converted cameras shoot at normal shutter speeds. With a 590 to 780 nm filter, I almost always use ISO 100 or 200 in sun or overcast, at around 1/100 second or faster at ƒ/5.6. A Candy Pink stack of three filters blocks more light, so I shoot it at ISO 800 to 1600.

Diffraction by Filter

Longer wavelengths diffract more, so the sharpest ƒ-stop gets wider as the filter number goes up. Pick your camera and filter in diffraction.cAm to see which ƒ-stops soften your photos.

White Balance and Editing by Filter

  • 665 nm and below: don’t white balance on foliage. Use clouds, pavement, or another neutral subject. See White Balance on Green Leaves with 550 nm Filter.
  • 720 nm: white balance on the foliage to make it white. White balance on a neutral subject for lightly colored foliage.
  • 830 nm and higher: edit as monochrome. Any black-and-white profile works, and no white balance is needed. See 850nm Infrared Monochrome in Lightroom Classic Full Edit.
  • Dual-bandpass and Candy Pink: no color swap. With a Candy Pink stack, a custom profile helps when the white balance hits the end of the scale.

For every technique, see White Balance for Infrared Photography and White Foliage Infrared.

Tools for editing by filter:

Filter Types and Accessories

  • Screw-in or clip-in: for the pros and cons of each form factor, see Clip-in Flange Filters.
  • Neutral density: ND filters made for infrared allow long exposures and wide apertures on a converted camera. See Kolari IRND Filters.
  • Stacking filters: use filters the same size as your lens thread or larger, with as few step-up rings as possible, to avoid vignetting.
  • Hot spots: many lenses show a bright hot spot in infrared. At 780 nm, even a mild hot spot can cause color banding in a pale sky. Check your lens in the Infrared Lens Database.