Using Adjustment Layers to 'Finish' a photo.

When I worked at a camera store many years ago, we were known as 'photo finishers' and that's honestly what we often did with customers pictures. When we developed a customer's film we would create prints from the negatives and it was the customer's expectation and our job to get the best image possible from those negatives - whether they were over exposed, underexposed, shot in a school gym under mercury-vapor lights or inside under incandescent bulbs. We would try to make the best prints for the customer we could by adjusting color and exposure and if they weren't happy, we'd reprint them again.

Somehow, that concept of 'finishing' has escaped most digital photographers; many accept what they get from their cameras as the final product. Well, folks, it ain't so. All professional digital photographers have a range of tools they use to create a digital workflow for touching up and adjusting their digital images. And, with some of the tricks you have learned here, you too will perhaps start thinking that taking the image and getting it into your computer is just the starting point in creating a digital image.

In this tutorial I'll introduce you to some additional tools that many digital photogaphers use routinely in their workflows to make adjusments to their images.

In the past couple of tutorials I have shown you how multiple layers can be used for borders, titles and making a collage of images. Now that the concept and power of using layers has been dealt with a bit, we can explore another aspect of layers - the adjustment layer. Up until now I have shown you how to make corrections on the image layer itself, but that results in altering the layer's pixels. By using adjustment layers you are essentially stacking a number of layers above the image that each changes how the image appears - yet the base image itself will remain unchanged. Think of this as layers of glass stacked above the image, one may slightly change the brightness, one the color balance, one the range of brightness levels in the image. When you look down from above you see the effects the layers have on the appearance of the image below, but that image itself will not be changed. This allows you to try many different adjustments - adding and deleting as you choose until you get the desired result.

Let's begin with a snapshot taken this past summer (2007) at the National Convention in Minnesota by my friend Greg Kaufmann.



Because the camera's meter was adjusting for the bright light off the variegated Hosta behind, this flower itself appears flat and underexposed. If you want to follow along, just right-click or Control-Click the image above and choose Save Image as... or whatever option will save the image to your local drive so you can open it in Photoshop.

The first things to find is where to add an adjustment layer. There are two places - one is in the Layers Menu above - pick New Adjustment Layer and it will pop out a submenu to choose from, or my preferred method is to create the adjustment layer in the layers palette itself.

On the bottom of the layers palette you will see a number of small icons, the one that's a circle - half white, half black is the one to click to create a new adjustment layer. Note here that there is a small black triangle beside the icon, this is like the triangles that appear on the tool palette, they indicate that another tool or menu will appear when you click the icon, in this case...

what appears is the options for the different kinds of fill and adjustment layers. We're not going to cover all of these in this tutorial, but concentrate on the four that are probably the most useful for any photographer trying to create a workflow for adjusting images. These are the four circled to the left. Levels - which controls where the dark, midpoint and light are in the image. Curves - an even broader set of tonal adjustments where up to 14 different adjustment points can be established and manipulated. Color Balance - where you can change the overall color of an image - similar to using color correction filters on a camera - this adjustment affects the whole image. And, finally Brightness and Contrast. Sometimes you will want to only use one or two of these on a image. Sometimes more. Note that there is a Photo Filter adjustment too, if you are familiar with the various color correction filters available for taking images, they can be found in here and applied after the fact as well.

I decided to start by adding a Levels Adjustment Layer - choosing the Levels option brings up a dialog box like the ones below...

Here's the levels before I made adjustments.

The graph (called a histogram) that appears shows the distribution of brightness levels throughout this image. Where 0 represents pure black and 255 bright white, the center slider can adjust the tonal range of the image by sliding it left or right - moving the midpoint toward darker or lighter. In the image above we can see that there blacks in the stone wall behind and bright whites in the hosta leaf. Since neither of these is our center of interest, we can make some adjustments to these levels and they will affect the background of the image more than they will affect the flower. Notice too that there is a Preview checkbox that's checked - that means that as you adjust the image by moving the three triangles under the graph you can see the effect on the image in real time as you make the changes. I played with the sliders until I got the flower to look a lot better. I 'clipped' some of the shadows and highlights, but since this is an adjustment layer, they are still in the base image below.

I moved the sliders to the points shown on the left. This is all trial and error and personal taste. My goal here is to bring the bloom into a state where it appears natural but retains the proper color and tones that I believe should be there. This is purely subjective and others may find different settings that please them. This adjustment layer got me closer to my goal. Side Note: If you take a number of pictures in the same location under similar lighting you can find a Levels Adjustment that appears to work and then use the Save... option and save that adjustment. Open another image, go to this dialog and Load... that saved adjustment. Second side note. At the top you'll see Channel and it's currently RGB - you can click in the triangles there and adjust the Red, Green and Blue Channels each separately as well. After making this adjustment, this is what the image now looks like.

Note that I sacrificed background details - there's now more washed out areas and deeper shadows. The flower is much improved, but still appears flat to me.

So, let's try adding another Adjustment Layer above and see if we can make additional changes to improve the image.

This time I go to the New Adjustment Layer menu and add a Curves Adjustment Layer.

The Curves Adjustment Layer starts out with the tonal range shown as a diagonal line. You can click on the line and this will add an adjustment point which can then be pulled to the left or right, or up and down to change that area of tonality. Again, this is highly subjective and you can go quite crazy here getting some pretty color banding and patterns. I typically create an "S" curve adjustment, moving the lower 1/4 point to the right a bit and the upper to the left a bit, but for this image it didn't work. Normally too these are very subtle adjustments that can be seen in the preview as you are working. I played with a number of attempts, before settling for the settings below.

Since the Hosta area appeared burned out, I actually dragged the white point at the upper right down some and added three midpoints and dragged them all to the right. Here, below, is the resulting image as it would appear through both adjustment layers.

Again, I was working toward improving the flower. Toward that end, I added another adjustment layer for Brightness and Contrast and made these adjustments.

One objection to the image above is that it's got too much contrast, so I pulled that down first in this dialog and then increased the brightness to bring back some detail in the throat that went AWOL when I made the contrast change. The final result appears below - putting your mouse on top of the image below and then pulling it off will show and hide the adjusted version and the final version after adjustment.

Now, when I save this image as a .psd I retain all the image layers and their adjustment settings, I can go back in later and alter them.

You can also click on the eye icon beside each layer to make that layer visible or hide it (when the eye is there the layer is visible.

To give you an idea of that - below is the image above with the Levels Adjustment Layer hidden...

And, again below with the Levels Layer back and the Curves Layer hidden...

You can see that each layer adjustment works with the others to eventually get something I was pleased with.

I encourage you to play with Adjustment Layers and make using them to tweak an image a regular part of your digital workflow when you 'process' your images.

My next tutorial will focus on Layer Masks, stay tuned...

Tim Fehr - Eau Claire, WI

© 2008 by Tim Fehr - all rights reserved.