So, this is the follow on tutorial from Part One.

This tutorial mainly focuses on the three other curves that we can adjust. In the first tutorial we manipulated the black line (RGB Curve), in part two I will show you how working with the individual Red, Green and Blue curves can produce some really nice effects.

Using the same image again, here are some examples of what the other Curves can do to an image.

Underneath the ‘Default’ drop down menu you will see another, ‘RGB’ by clicking on this you will see three further options.

I will start with the Red Curve.

You will see that by adjusting the line you produce two different colours of the overall image. Any points moved to the left of the line will become warmer (red) and anything to the right will become cooler (blue/green). This change in colour is also the case in both the Green and the Blue Curve.

Next, the Green…..

….. and finally the Blue.

Any point moved over the line, in either direction, will create a change in colour.

Below is an example of how using these Curves together can produce some nice results.

I just wanted to explain in a little more detail what these histograms are showing for the unfamiliar.

Basically this is a histogram split into the three colour channels, but the overall histogram works in the same way. The bottom left signifies black and the bottom right is white, and across the bottom you have every tone in between. The height of the peak shows how much information is in each area of the picture.

The adjustments to blue here have brightened the blues in the picture when they’re at their darkest and the increase becomes steadily less significant as the tones brighten. The reds have been darkened in their dark area and lightened in their light area, but not at their black or white points, which adds contrast to the reds in the image.

The next stage to this tutorial is how to incorporate the adjustment of these curves into image processing. I have chosen a different image for this purpose, a portrait (of the very handsome sophos9

).

1. Open image in Photoshop (I use CS5). Add new adjustment layer – Layer > New Adjustment Layer > Hue/Saturation. Adjust Saturation to -20.

2. Layer > New Adjustment Layer > Curves > Change RGB to Red and adjust as seen below.

3. Layer > New Adjustment Layer > Curves > Change RGB to Green and adjust as seen below.

4. Layer > New Adjustment Layer > Curves > Change RGB to Blue and adjust as seen below.

This technique is quick to use, in four steps you can take an image…..

….. and give it a colour cast which creates a completely different feel.

This technique can also be used with black and white images.

1. Open image in Photoshop (I use CS5). Add new adjustment layer – Layer > New Adjustment Layer > Black & White. Adjust image to required black and white settings.

2. Layer > New Adjustment Layer > Curves > Change RGB to Red and adjust as seen below.

3. Layer > New Adjustment Layer > Curves > Change RGB to Green and adjust as seen below.

4. Layer > New Adjustment Layer > Curves > Change RGB to Blue and adjust as seen below.

As shown above in the colour image, using four easy processing steps can produce a cool processing style.

Before

After

Hope you guys find this helpful… if you have any questions please ask away

If you have a tutorial you would like to see, then please let us know here.