Click on any image to see it larger (If you are on a PC at least).

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Introduction

Capture One is generally thought to not be a very capable infrared editor though as I will show, this is not the case.  I will also briefly touch on processing in Photoshop and Lightroom.

This is a technical post that is mainly of interest to those shooting infrared, or contemplating doing so, and also processing in Capture One, or contemplating doing so.  Others might skim down to see the processes of image transformation without bothering to contemplate the details of how it is done.

I have more information on what infrared is all about in my previous post Introduction to Infrared Photography. Processing is particularly important to most forms of digital infrared photography, particularly where you are starting  with a colour image.  

Taking Infrared Images

The wavelength of visible light ranges from 400 nanomentres (nm) (violet) to 750 nm (red).  At less than 400nm there is ultraviolet light and at more than 750nm there is infrared, neither of which we can see.  Digital cameras however, record colours from around 350nm to 1,000nm, more than we can see, and usually have “hot mirror filters” to block UV and IR light in the interests of recording more accurate colours.

You can take infrared images using either a filter over the lens or a converted camera in which a filter allowing infrared light to pass replaces the hot pass filter.  I have a camera with a 560nm conversion, which allows bright colours and includes both visible light and infrared.  The most common filter (and maybe conversion) is 720nm which admits less visible light and more infrared and has reduced colours.  An 800nm filter or conversion is infrared only and produces a black and white image only.

An image from an 800nm filter may require little processing.  For lower-nm filters, it is possible to use a custom white balance and maybe be satisfied with that, though much more is possible.  I aim to transfer the image in post-processing so I don’t bother with a custom white balance and to aid that process I also shoot RAW.

Processing in Photoshop and Lightroom

A few years ago, Photoshop was the primary method of post-processing (and probably still is for most people).  A key part of this was channel swapping, for example, swapping red and blue channels to get blue skies.  You might also make other adjustments using layers for hue/saturation, black and white (with luminosity blending) and selective colour, and even get really complex with luminosity masking or the Orton Effect.

Using Lightroom for infrared images required generating and using a camera profile to extend the range of colours Lightroom sees.  If processing in Photoshop, I would first make adjustments in Lightroom including changing the colour balance to maximise separation of colours. and might also make other adjustments including in the calibration tab and curves adjustments by colour channel.  Only then would I launch to Photoshop from Lightroom.  What you got your starting image to look like would affect the range of possibilities in Photoshop.

A year or two ago, Lightroom introduced Profiles and it became possible to export LUTs from Photoshop to become channel swapping profiles in Lightroom.  So it is now possible to do your processing in Lightroom, though there is more capability in Photoshop.  Rob Shea provides information on how to make your own Lightroom channel-swapping profiles or buy some from him.

Processing in Capture One

Preparation

Unlike Lightroom, Capture One already has a full  range of available colours for infrared processing without the need for a custom camera profile.  However, it been seen as a not-so capable processor for infrared. Not so, as I will show you….

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This is how you might start out, an uncorrected image out of the camera (appearance will vary according to infrared filter).

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This is what it looks like after moving sliders for colour temperature and tint to maximise colour separation, and after clicking Auto Adjust for levels.

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Iterative Process for Channel Swap

(Click on images if you need to see more detail).

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I have created several Editor presets in the colour editor, using a method as shown in this article.  It is important to do this on separate layers, as it can get confusing if you try to do it all on the background layer. 

To create a red/blue colour swap preset, you make a selection for the red sector of the colour wheel.  Then you change the hue four times by -30° for a total change of -30° (out of 360).  That’s for the red shift.  For the blue shift, you select an appropriate blue segment and move it four times by 30° to shift it to red.  Then you save it as a custom preset.  Once you have the custom preset, you can select it for an instant effect.

The red/blue colour swap works OK for this image.  The equivalent of a Photoshop channel swap requires combining the red/blue colour swap with a cyan/yellow colour swap.  These Color Editor presets also work on layers so it is possible to have different colour swaps or channel swaps on different layers and combine them using layer opacity.

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The easiest way to create such custom presets is off an image of a photographic colour wheel.  You use the colour picker tool in the Colour Editor (tiny yellow tool on the black background to bottom right of the destination colour wheel), adjust hue, unclick, reclick and repeat. Then you can see the colours change as you go.  Its’s best to have only one colour change selected at a time or the results can get confusing.

I had to adjust the orientation of my colour editor segments a bit due to colour inaccuracy in the image I was using.  Red and cyan should align around the horizontal axis, and the other colours around the vertical axis.

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So this is what I get after next clicking on my red blue swap preset in the Advanced tab of my Colour Editor.

The above example combined a red/blue colour swap with a cyan/yellow colour swap.  You could save these as two separate presets, or other combination as desired.  So each of such presets has multiple saved steps and you can uncheck some of those steps in the interface shown above to get intermediate colours. 

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Direct Changes with the “Skin Tone” Editor

Now the next thing is I want to change the yellow-green colour in the landscape.  I could use the incremental change method as above but there’s an easier way.

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Now we go to the Skin Tone tab of the Colour Editor.  Once again, use a new layer or it can get confusing, though you will probably delete this layer later.  Use the picker to select the colour you want, in this case the foliage of the landscape.  Adjust this if required.  In the menu for the Colour Editor, select Create Masked layer from Selection. That creates a new layer with the foliage part of the landscape selected.  Sometimes this gives you a larger selection than you wanted, in which case you will need to reduce the initial selection and try again, or sometimes you can just use the eraser to reduce the created mask.

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Now in the new layer just created, we go to the Skin Tone pane in the Colour Editor again.  (We are going to change the “skin tone” of the foliage).  The critical thing here is to have the Hue Uniformity slider all the way to the right, as shown.  Then use the picker to select the desired colour again (in this case, the landscape foliage).  Next, drag the selected segment in the colour wheel around to expand it from say 20° or 30° to nearly 360°.  There’s a small handle, opposite the unselected segment and in this case at the bottom-left of the colour wheel.  You can grab this and rotate the colour wheel, changing the colour to whatever you want.    Since we are on a layer where only the foliage is selected, only that colour changes.  Try also moving the bottom sliders for Saturation and Lightness if you want to change those as well.

You can also use this method as a more direct method to change colours than the Iterative Channel Swap process.

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Now we have the landscape foliage colour changed.

Final Adjustments

The last thing I wanted to do was to change the colour of the foreground foliage of the small trees against the sky.  I created another layer, copied the mask from the initial layer, erased all of the mask except for the small trees and then changed the colour.  There were a number of ways I could have done this and I just used colour balance.

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So this was the final image, also cropped a little further.  I may have also made some other minor adjustments not specific to infrared.

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There are many styles of infrared photography and if you are using a different filter or conversion to me, your range of possibilities may be quite different.  I could also have processed this image in Capture One for quite different results.

I have related a few techniques here that may be useful for people using Capture One to interpret in their own way.  Most people opt for a limited range of colours and perhaps minimal processing.  All approaches are valid; it’s only what you end up with that counts no matter how much or little effort you put into it.

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