False-colour Infrared Photography

False Colour Infrared (FCIR) or Infrared False Colour (IRFC) photography is a method used to identify certain pigments as well as certain inks, e.g. iron gall ink. FCIR combines a visible and an infrared photograph and requires a fair amount of post-processing.

False Colour Infrared photography procedure

1. Use the Fuji S3 Pro camera for the whole procedure.
2. Set everything up in the same way as you would do to get a visible light photograph!
3. Make sure that the camera is set to “M” mode.
4. Attach the B&W 486 IR cut-off filter to the camera.
5. Adjust the exposure speed to find the best exposure.
6. Ensure that your object is in focus (use auto focus for this by making sure that the dial at the front of the camera is at the “S” position).
7. Proceed with taking your photograph.
8. Without moving the camera at all, remove the B&W 486 filter.
9. Set the focus to manual (turn the dial at the front of the camera to the “M” position)!
10. Set up your light sources in the same way you would to take an infrared photograph.
11. Attach the B&W 093 IR filter to the camera.
12. Proceed with taking a normal IR photograph.
13. Open both images in Photoshop.
14. Adjust the IR image as you would normally do.
15. Start with the visible light image.
16. Go to Window --> Channels to view the RGB channels of your image.
17. Select the Blue channel (Click on the Blue Channel or press Ctrl+5 or Cmd+5 on a Mac).
18. Select the whole image (Select --> All or press Ctrl+A or Cmd+A on a Mac).
19. Hit the Delete button.
20. Set the Fill to Black.
21. Your image should now lack any blue colour.
22. Next step is to transfer the Green channel to the Blue channel.
23. Select the Green channel (Click on the Green Channel or press Ctrl+4 or Cmd+4 on a Mac).
24. Select the whole image (Select --> All or press Ctrl+A or Cmd+A on a Mac).
25. Copy the image (Edit --> Copy or press Ctrl+C or Cmd+C on a Mac).
26. Select the Blue channel (Click on the Blue Channel or press Ctrl+5 or Cmd+5 on a Mac).
27. Paste in the Green channel (Ctrl+V or Cmd+V on a Mac).
28. The next step is to transfer the Red channel to the Green channel.
29. Select the Red channel (Click on the Red Channel or press Ctrl+3 or Cmd+3 on a Mac).
30. Select the whole image (Select --> All or press Ctrl+A or Cmd+A on a Mac).
31. Copy the image (Edit --> Copy or press Ctrl+C or Cmd+C on a Mac).
32. Select the Green channel (Click on the Green Channel or press Ctrl+4 or Cmd+4 on a Mac).
33. Paste in the Red channel (Edit --> Paste or press Ctrl+V or Cmd+V on a Mac).
34. The next step is to transfer your infrared image to the Red channel.
35. Open your Infrared image.
36. Select the whole image (Select --> All or press Ctrl+A or Cmd+A on a Mac).
37. Copy it (Edit --> Copy or press Ctrl+C or Cmd+C on a Mac).
38. Go back to the visible light image.
39. Select the Red channel (Click on the Red Channel or press Ctrl+3 or Cmd+3 on a Mac).
40. Paste in the IR image (Edit --> Paste or press Ctrl+V or Cmd+V on a Mac).
41. Due to the difference in focus you will see that your IR image does not align properly.
42. The next step is to resize the Red channel.
43. Select the Red channel (Click on the Red Channel or press Ctrl+3 or Cmd+3 on a Mac).
44. Select the whole image (Select --> All or press Ctrl+A or Cmd+A on a Mac).
45. Go to Edit  Transform  Scale and hold down the Shift key while resizing the IR channel. Do not remove your finger from the Shift key until you have finished resizing your image!
46. To make sure that you get a proper alignment, zoom into an area of the image and with the Red channel selected, select the whole image as described above. Finally, press and hold the Ctrl or Cmd (for Macs) key while moving the arrow keys. Once done hit Return/Enter.
47. Crop the image to the area needed and save as a TIFF file as usual.