ORIGINALLY POSTED BY ALLY FOR THETAZZONE/TAZFORUM HERE
There are many methods of simulating an infrared effect in Photoshop, I think this is one of easiest.
You can always rush out and buy an IR filter if you want as well
You’re going to be using a B&W adjustment layer in CS3 and turning a layer into a smart object. So lets get straight into it, you can click through on the image below for the larger version if you want to practise on it. All the settings will be relevant to this particular image 800 x 600 @72dpi you will need to adjust them for larger images.
Using a B&W adjustment layer – click on the adjustment layer in the layers palette and choose B&W – you can punch in the same numbers that I have in the image below. You are looking to boost the greens, and depending on the image, may also have to boost the yellows as well.
Click on the background layer to make it active, then right click on the layer and choose ‘Convert to Smart Object’ from the menu. Then go to Filter>Blur>Gaussian Blur. On this particular image, choose a radius of 5 pixels. See image below.
Referencing the image below, double click on the small upward facing arrows next to where it says Gaussian Blur in the Layers Palette. This will bring up a small dialogue box, adjust the opacity to 50% and click OK to accept the change.
Click on the b/ground layer to make it active, then hold down the Alt key on the keyboard and click on the create new layer icon at the bottom of the layers palette. The New Layer dialogue box will appear – you can name the layer if you want – change the blend mode to Overlay and check the ‘Fill with Overlay Neutral color (50% gray) box.
Making sure you are working on the new layer you created (should be gray) go to Filter>Noise>Add Noise and on this particular image choose about 5% – Gaussian – Monochromatic. Then lower the opacity of the layer to about 35%
Finally, click on the top most layer (B&W adjustment layer) and click on the create new fill or adjustment layer icon at the bottom of the layers palette, then choose curves from the menu. Create an S curve until you get something that you are happy with. You can punch in the same numbers I have in the image below if you like.
And here is the final image. You can change any of the settings to suit your own taste. There is probably a little too much greenery in this image as well