| If I don't post now, it will be two days before I can get back to this. Here is an explanation of the "updated" infrared technique by Martin Evening as published in the Dec 2001 issue of PEI magazine:
1. Create a Channel Mixer adjustment layer, setting the green channel to 200% and the red and blue channels to numbers that add up to -100% (notice the minus sign). This will give an overall 100% sum for all three channels. In the example in the magazine, he used -30/200/-70, but I think it depends on the picture.
2. There is a good chance that the numbers above (esp. the 200% value for the green channel) will blow out the highlights. To get the detail in the highlights back, make the background layer active and create a Curves adjustment layer. (The Curves layer should be between the Background and Channel Mixer layers.) Select the green channel in the Curves dialog and drag the highlight point of the green curve down to reduce the brightness of the highlights. (In the example, it looks like he lowered the point about 12%.) This should restore detail in the highlights that were lost.
3. If there is any sky (with clouds) in you picture, they are probably lacking contrast at this point. So, open the Layer Styles dialog box for the Curves layer and select the red channel layer blending options. Alt-drag the left triangle of the highlight for "This Layer". This will split the slider and help increase the contrast in the sky/clouds. (In the example, it looks like he moved the slider to 160/255 values.)
4. Now you want to add a "glow" to the trees. Duplicate the Background layer and Gaussian Blur at 5.0. Then fade the filter to somewhere between 25-50% and set the blending mode to screen. Unfortunately, this may cause the highlights to blow out again.
5. So, open the Curves adjustment layer and create a contrast-reducing curve (i.e., reverse-S), so that the angle of the curve in the center is less than 45 degrees. This should again restore the highlight details.
6. Infrared should look grainy, so make the Background Copy layer active and apply the Add Noise filter using a value between 3 and 5 (make sure you check the monochromatic box.)
7. You could stop here for a nice infrared B&W, but if you want to add a little color back, open the Channel Mixer layer again. Uncheck the "monochrome" box. You won't see a change until you move one of the sliders. But then a color adjustment will appear, based on the underlying color image. In the article, the following "experiments" were shown:
a. Adjust the settings of the red channel to: +6/+194/-102.
b. Leave those settings in place, then go to the blue channel and adjust to: -26/+174/-81, Constant: +13.
c. Return to the red channel and change the settings once again so that the trees look green and the sky red: -28/+187/-40.
*NOTE*: Martin Evening suggests that you make small, careful changes to the sliders in the Channel Mixer because even a small percentage change can create a huge shift in the overall colors.
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The action which I provided a link to in my previous post takes you through step 6 (I think). Then there are Color Adjust actions you can apply or you can play with the sliders in the Channel Mixer yourself if you want to add some color back.
Hope this helps,
Jeanie |