How to digitally do the red-green-blue thing

[Didache]

Hi all .. as a couple of folk have asked how I did the red-green-blue thing digitally, here goes! If anyone experiments with this and has any other questions, my email is mg.dales@btinternet.com - feel free!

Now, the technique requires that some parts of the image are stationary and some are moving (people works best).

For the purpose of this demo I took a number of pctures just down the road of some moving cars. The result is NOT a prize-winner, but just for demo purposes. Not everything works - the key is to experiment. Some subjects will work well, others won't. Use a tripod and take quite a number of pictures on your digital camera. It is essential that the pictures are identical, except for the moving elements. On the computer pick your best three pictures (best in terms of the positions of the moving elements).

I did this on Elements 4 - other programs might have a different workflow. I took one of my pictures, and clicked Enhance/Adjust colour/Colour variations - and clicked the Increase Red 5 times. The result is picture 1. It doesn't matter how you do this - what you need to wind up with is a picture dominated by the red channel. Do exactly the same with the other two pictures, except that one is increased blue, and the other with increased green. Make sure you save-save-save at each step.

Now, copy each of your red-green-blue pictures to a layer and set the opacity of each (initially) at 25%.

Use the Move control to put the layers on top of one another. (In Elements 4 this is done by holding down the Ctrl key and using the move control to shift the pictures.) If the layers are locked (a feature of Elements 4) you may have to copy the backgrounds to layers too.

You will wind up with a muddy looking thing - picture 2.

No matter how sturdy your tripod, the three pictures in your image will probably not line up precisely. Magnify the image to something like a road sign and, using the layers pallette to click between the three layers, do micro movements so that all three layers line up.

Now the tricky bit. you need to adjust the opacities of each of the three layers so that two things happen: a) the stationary bits revert more or less to their normal colour. b) more important, so that the moving elements of all three layers come through with similar intensity. You will have to play around with this quite a bit. The result is picture 3.

Finally, you need to adjust the colours - flatten the image (under the layers tab) and call up hue-saturation adjustment. Again, you will need to play around with this quite a bit - but invariably the saturation will need quite a lot of boosting. The final result is picture 4 - again, please bear in mind that this is only a demo. The technique works much better in bright conditions.

Hope all that's clear!
Cheers
Mike (didache)