Photography Tutorial:

Simple use of a curves adjustment layer

Digital cameras try to average out a scene rather than expose for highlights or shadows. Many times this can lead to an image that comes out rather "flat". This tutorial shows a very simple technique using a curves adjustment layer to make dramatic improvements to the dynamic range and contrast of a photo.

Here is a photo I took in a museum in Italy earlier this year. There were large windows on the other side of the room letting in lots of light. The resulting photo, while having "ok" color looks pretty flat to me.

So, let's start by adding an adjustment layer. I'm using Paint Shop Pro 8 here, but you can do the same thing in Photoshop Elements and many other graphic editing programs. There are many types of adjustment layers, so here we're going to use the "curves" adjustment layer.

Regardless of your editing program, you'll have a window that shows a diagonal line across a grid. The grid area is a representation of the histogram, going from pure black on the left to pure white on the right. The corner to corner diagonal line represents no modification to the underlying picture.

Now the first thing we want to do is add some anchor points at the grid intersections. These will allow us to manipulate individual sections of the curve without affecting the others. Simply left-click on the curve to place the points. If you place one in the wrong location, simply drag it off the grid to eliminate it.

Now what we want to do is apply what's called an S-curve adjustment. Drag the lowest anchor point down a bit and the highest anchor point up a bit. The more you move them, the greater the effect.

You can see how the diagonal line now represents an "S" shape. Go ahead and apply the changes. In my case that means clicking the OK button.

You should see a dramatic change to your photo. Sometimes, this can lead to some of the colors being a bit too vivid, so let's reduce the effect just a bit by dropping the opacity of the adjustment layer down from 100% to 70%.

Now, here's a little trick to mute the sharpest colors and add contrast to the overall photo. Duplicate the adjustment layer (creating a third layer) but change the adjustment type from curves to "luminance" and drop the opacity from 70% to 50%.

Adjust the opacity settings for each layer until you get the look you like. Now let's compare the before and after pictures. Move your mouse back and forth between the thumbnails to see the effect.

Happy shooting,