Digital Infrared

How to Take an Infrared Photo, and how to

Swap the Channels to get Blue Skies

Ingredients:

 

1. A digital camera that is sensitive to infrared light.

2. An infrared filter - common ones are the Hoya R72, and the Cokin 007

3. A tripod.

4. A bright, sunny day - works best.

 

Method:

 

1. Make sure the camera is set up to take RAW images (not JPEG or tiff) - so we can fine tune the white balance in Photoshop afterwards.

 

2. Set the custom white balance on your camera - by putting the filter on and then aiming at some brightly lit grass - if you’re not sure how to set the custom white balance on your camera - check your manual!

The reason we are setting up the WB on grass is because we are telling the camera that we want everything grass coloured in visible light to appear as a neutral colour (hopefully white) in the infrared image.

 

3. Set the camera up on a tripod - this is necessary as the exposure will be quite long, and you will get camera shake if you try to hand-hold it.

 

4. You won’t be able to compose your shot with the filter on (because you cant see through it!!) - so compose your shot before putting the filter on.  Scenes with a mix of foliage and man-made elements turn out well.

 

5. Once you’ve composed the shot and put the filter on, make sure the camera is in ‘aperture priority’ mode.

The reason you want to have control over the aperture is because a small aperture (big F number - like f22) will leave you with a hot-spot in the middle of your photo, and as you’ve got a tripod, it doesn’t matter how slow the shutter is.

 

6. Set the aperture to about f6.3

 

7. Take the picture (don’t panic if it looks very red), and then check the histogram - if it looks very dark, either add exposure compensation, or go to manual mode and select the same aperture but a slower shutter.

 

8.Once you’ve downloaded the photos to your computer, open them in Camera Raw and further tweak the white balance by clicking on the white balance tool in the top left hand corner, and then clicking the eye dropper on whatever you want to appear neutral in colour - sometimes the green foliage, sometimes the clouds etc.

 

 

9. The photo will most likely still look red - but open it anyway.

 

10.With the image open, go to:  IMAGE >> ADJUSTMENTS >> CHANNEL MIXER.

The channel mixer box opens on the red channel.  Move the red slider to 0 and the blue slider to 100.

 

 

11. Then, from the output channel drop-down menu, select the blue channel.

Slide the blue slider to 0 and the red slider to 100 and click OK.

 

 

12. Now go to IMAGE ADJUSTMENTS and do the following three commands

‘Auto Levels’, ‘Auto Colour Balance’ & ‘Auto Contrast’.

 

You should now have an image where the sky is blue and most of the vegetation is white(ish).