Infrared processing in Photoshop

[IainB]

Can anyone remind me of the best way to remove the magenta cast from IR images in photoshop? I don't simply want to desaturate the image. I seem to recall a technique (posted by "Jim"?) which preserved good image quality and also gave a curious green tone to parts of the image. It may have involved channels, but I just can't recall.

[Digital Prophet]

The simplest way is: Open the image in PS.
Change the image mode to CMYK (Image -> Mode -> CMYK Color)
Open the Chanel Mixer (Image -> Adjustments -> Channel Mixer)
Select "Magenta" from the Output Channel pulldown (or hit "CTRL+2")
Move the Magenta Slider (second from top) to the left to the desired level.
Be sure to have "Preview" checked so you can monitor the change in the image.

- Digital Prophet -