Thursday, 16 October 2014

Infrared Colour Conversion: A Workflow in the Mac using Aperture, Photoshop Elements plus Elements+, and Nik Software

As followers of this blog may realise, I have been playing with infra-red converted cameras over the past year. I have been trying to achieve a protocol or workflow that includes the channel mixer step to swap the red and blue channels as well as to provide local as well as local control over what appears in the final image.

Over the past few weeks, urged on by the acquisition via eBay of a 590 nm cut-off filter in a Nikon D80, I came up with the following protocol. Last year I bought a 715 nm-converted D70. The 590 nm is the ‘Super Color’ filter of Lifepixel; the 715 nm is the ‘Standard IR Filter’. Incidentally, for those wanting to get into colour infra-red photography, the videos on the  Lifepixel website are the best I have come across.

The protocol is not perfect because it does not move the original raw files between applications and the channel swapping is done at 8 bits, not 16.

The starting point is a raw NEF file in Aperture 3. This workflow uses Aperture to store and stack the converted images. However, since Aperture will not be supported by Apple in the foreseeable future, it is important to note that no essential steps are taken in Aperture.

In Aperture Preferences, export files are set to PSD with Photoshop Elements as the External Editor (TIFFs could also be used). Nik Collection’s Viveza 2 and Sharpener Pro 3 Output Sharpening are plug-ins from Aperture.

I am not giving details of what I do within each piece of software. Topics like channel-swapping and how to use Nik software control points are very well covered elsewhere.

The raw file is imported into Aperture. This is what it looks like:

No Adjustments are made to the image in Aperture. Using ‘edit with Adobe Photoshop Elements.’ the image then opens in Photoshop Elements with Elements+ incorporated. That’s where the red and blue channels are swapped. After saving and replacing the image that arrived in Elements, the channel-swapped image arrives back in Aperture alongside and in the stack of the original version. This is what it looks like at that stage:

Then, using ‘edit with plug-in’, the image is opened in Viveza 2. There, the world is your oyster because the level of control is immense. I first do global adjustments using mainly the Levels and Curves panel. I then make control points to control the colour, saturation, brightness and contrast  of individual areas. For example, I can make the foliage colour more golden (from the 590 nm filter) or I can desaturate it completely to white. Nik’s U-point technology really comes into its own for sort sort of work. I then press Save and the image reappears in Aperture.

In Aperture I using the retouching tool to take out any minor imperfections. A bird, for example, in the distance may look like a black speck.

The I sharpen the image, either in Aperture or in Sharpener Pro 3 Output Sharpening, accessed again as a plug-in. Sharpening the whole image can bring unwanted texture into the sky, for example. However, control points can be set to then reduce that added sharpening in the sky. Indeed, the sky can be de-sharpened independently so far that the image can be made to appear as if a long exposure was used with the edges of the clouds merged into the sky. After pressing Save, the image again appears back in Aperture.

Finally, I straighten and crop the image if necessary in Aperture.

This is what the output can looked out, bearing in mind that a very wide range of ‘looks’ is possible from a basic infra-red end of the spectrum image.

So that, for the moment at least and until I come up with something better, is my standard protocol.