Today we are going to look at why curves in Photoshop can improve all your photos.
Many photographers can be daunted by the sheer wealth of editing tools that
Photoshop has to offer. Because of this, they might tend to stick with the tools they are most familiar with. The tools they learnt first.
Like many, the first tool I learnt to use for exposure control were levels. However, I soon started to delve into the wonders of the curve tool and I have never looked back since.
Our original image
What Do Curves In Photoshop Do?
Photoshop, a curve allows you to brighten or darken a specific point in the tonal range of your image. The original image should open having its histogram panel open. If not go to Menu – Window – Histogram to show it. Our image with the histogram overlaid
The top right of that line represents the very brightest part of the image. The bottom left represents the darkest point. In the screenshot, we can see that we have a peak of tonal range to the left side. This is the dark green of the trees surrounding the castle. The secondary peak to the right is the highlights of the sky and the misty part of the landscape. To demonstrate the power of curves in Photoshop on exposure, we are going to edit this image to raise the shadows and add definition to the sky. To do this, we will create a new adjustment layer rather than working directly on the image.
Creating An Exposure Curve.
Photoshop Curves has an excellent and simple tool to help us identify the exact tonal point we wish to modify. It's an eye dropper and can be selected by clicking on the hand tool underneath the word Preset. To start the curve, click and drag up or down at the tonal point you wish to change. Dragging up will lighten the tone, dragging down will darken it.
It’s usually best to start with the darker tones, and in this case, I have selected an area of dark green trees and lightened the tone. As you can see we now have a much better definition in the tree-line around the castle without affecting the rest of the image.
Using the eyedropper to determine the shadows areas
Now we are going to add some definition to the sky. To do this, I click and drag the eyedropper tool down in the sky tone that I wish to work on.
Dragging the upper right down a little adds some detail to the sky
The overall image looks a little flat, so we are going to bump the contrast a little with some manual adjustments to the curve. At the very bottom right I have dragged the curve line inwards a little. This has made the set the darkest tone to pure black.
At the top right of the graph, I have lifted, very slightly the lightest part of the image. This combined with reducing the black level has boosted the contrast nicely. Now a less known aspect of curves, colour manipulation.
Correcting or Adjusting Color With Curves In Photoshop.
Although the image looks pretty good now, it lacks that dawn feel to the colour tones. Curves don’t only allow you to adjust the exposure but also you can make tonal adjustments in the red, green and blue channels. In other words, you have a high degree of control over colour too. To select a colour channel simply click on RGB and change it to the colour of your choice.
In my case, I have selected the blue channel in order to add a little more yellow to the sky and trees. Selecting a region of the sky, I have dragged up to add a little more yellowness. I have done the same for the tree area as well.
Making adjustments to the blue curve only
Because I feel that the image is a little green overall,
I will now add some magenta to the mid-tone areas. I select the green channel, then put the eyedropper on one of the lighter toned trees and drag down. This adds a little magenta to the image, reducing the greenish tinge. Adjusting the green curve to add some magenta
You can adjust virtually any colour using a combination of the red, green and blue channels.
The adjusted image
Curves: You Will Never Look Back
Once you start to realise the sheer power of a curve, you are unlikely to go back to more basic adjustments such as Brightness/Contrast or levels. By using a Curve Adjustment Layer rather than working directly on the image, you can easily undo things if you go too far, or delete the layer and start again.
The next time you fire up Photoshop for some basic editing, have a go with the curves tool and be prepared to be amazed at the control you have.