Colour Infra Red Film Effects.
This technique simulates the effect of Kodak colour infra red film. Foliage tends to go red/magenta on this emulsion. This technique has recently been revived due to Richard Mosse’s “Infra” documentary series on rebel’s fighting in the Congo.
This can be simulated well on a similar kind of colour image that again contains leaves, trees etc.
The first thing to do is convert the mode from RGB to CMYK. This technique will not work in RGB. (image > mode > CMYK Color) Do not flatten the image .
Once in CMYK, we need to copy colour information from one channel to another. Select the Channels palette, and then select the Yellow channel. Press command +A (ctrl+a on a PC) to select the whole image for the yellow channel. Copy that channel by pressing command+C (or use edit/copy). We then paste this into the magenta channel by selecting that channel and then pressing command + V to paste it into the magenta layer. Then select the CMYK channel. The image should now start to look like a colour IR shot. We still need to tweak the image slightly using the channels mixer.
Select the channel mixer from the adjustment window as shown above. Once the channel mixer is open, adjust the Cyan and Yellow channels as shown below.
The image should now start to look very close to a real colour infra red shot. However, if skin tones were present in the image (like the one used here) then we may have to restore skin tones by using the layer mask on the background copy layer.
Then we can “paint” the original skin tones back in using a black brush. The last thing to do is convert the image back to RGB before any further editing. Image/mode/RGB . Select flatten .Doing this will flatten layers, and PS will warn you about this. To avoid the dialog, you can flatten the image first, then convert back to RGB. Finally, do a curves adjustment later if any excess yellow still exists. You should now have an image like the one below. Finally increase magenta by creating a hue/saturation adjustment layer . And set the Red channel’s Hue to -15 .Finally, with a black brush, brush back the skin tones on the Hue/Saturation’s Layer Mask .Convert the background layer to a smart object by right clicking (cmd+click) . Select Camera Raw Filter from the filter menu .Once in ACR… select the FX filter tab, and increase grain as shown below.As Kodak High Speed Infra Red Colour Film is a fast, grainy film, this completes the effect. (If you resize the image while the smart filter is still active, you’ll need to re-adjust the grain size in ACR by double clicking on the Camer Raw Filter in the layers palette) .