CHAPTER 6 WORKING WITH ADJUSTMENT LAYERS (or CURVES glorious curves) Part 1: CORRECTING contrast!

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1 Introduction to Photography and the Digital Darkroom by Edie Bresler 46 CHAPTER 6 WORKING WITH ADJUSTMENT LAYERS (or CURVES glorious curves) Part 1: CORRECTING contrast! Adjustment layers are non-destructive ways to edit photographic files. The effects are layered on top of the background so your original remains unchanged and locked. In this chapter we will use layers to enhance overall or global contrast. My favorite adjustment layer is curves because often anything you can do with levels or brightness/contrast, you can do more precisely, and therefore better with a curve. Always SAVE your layers with the working file so after seeing a print, you can edit layers as necessary, without changing your original. This is the key to non-destructive editing. Each curve is represented by a graph with three main regions: highlights, mid-tones and shadows. There are two ways to access and create adjustment layers: The first is by clicking on the adjustment icon: The default RGB curve is a straight diagonal line like the one on the left. Highlights are located in the upper region, mid-tones near the center and dark colors and shadows in the lower region. The bottom point is zero and the upper most point is 255. The center point is 128. The target adjustment tool on the left side is used to indicate where areas of your file are located on any given curve. As you hover over an area of the file, a corresponding point appears on the RGB curve. This is the adjustment panel icon. Double clicking on the arrows at the top right expands the panel so you can access all the adjustments.

2 Introduction to Photography and the Digital Darkroom by Edie Bresler 47 The three icons highlighted represent from left to right: brightness/contrast, levels, and curves. These are the three you will rely on most in Photoshop. If you hover over an icon with your mouse, an identifying yellow tool tip will appear. Clicking on the top right double arrows will collapse the window back into the icon. The second way is through the layers panel. Click on the adjustment icon at the bottom of the layers panel and scroll to the adjustment layer you want to add. Correcting contrast in curves is always done in the composite RGB channel: Making a simple contrast adjustment with curves Before we start making adjustments, let s define what we mean when we talk about contrast. It refers to the overall range of brightness to darkness in a photograph. Images with good contrast are lively and make the best prints. All images look great on monitors the real test is how they look as color prints. On the following pages I ll show you an example for altering contrast using a simple adjustment curve.

3 Introduction to Photography and the Digital Darkroom by Edie Bresler 48 This photograph was taken in a marketplace outside Mexico City on a cloudy day. The contrast is dull and flat. I m going to use curves to brighten the highlights and mid-tones, while leaving the shadows nice and deep. After clicking on the target adjustment tool, point #1 was taken from the white area of the background posters. I chose her skin tone for point #2 at the bottom of the midtone region. I used the black lettering to place point #3 in the shadow region of the curve. I don t want the shadows (i.e. letters) to get any darker or lighter so I won t move this point at all. Instead it acts as a kind of anchor. When I raise the other two points to lighten mid-tones and highlights, the shadows will remain unchanged. I use the arrow keys (rather than the mouse) to move points because you can accidentally move a point side-to-side adversely affecting color. To cycle between points use keyboard commands: To cycle forward (left to right) through curve points, press +/= key. To cycle backward through curve points, press key (that s the minus sign).

4 Introduction to Photography and the Digital Darkroom by Edie Bresler 49 Notice that the adjustment resembles an S- curve. All adjustments (when possible) should use an S-curve model: highlight adjustments move up; shadow adjustment move down. This increase in contrast improves print contrast. After choosing three points and adjusting them up and down along the curve the overall contrast of the scene is much improved: If you double-click on the word curves, you can rename the adjustment layer. This becomes really useful when you have multiple layers. Re-name it with its function, such as contrast

5 Introduction to Photography and the Digital Darkroom by Edie Bresler 50 Levels Adjustment layer Levels allow you to alter the contrast of a photograph using a shadow (1), mid-tone (2) and highlight (3) slider. To make adjustments, you can click and drag the sliders at the bottom of the histogram or highlight and change the numbers in the corresponding windows. The default settings are pure black at zero (far left) and pure white at 255 (far right). Mid-tones are set at 1.00 To improve the contrast of your image, drag the shadow and highlight sliders so they rest at the foot of the histogram mountain, where it starts to slope upwards. Levels are really useful as masks or to quickly brighten an area. Here are few different histograms: Good range of contrast Underexposed or Overexposed or image taken in low light image taken in bright light Sometimes depending on the light of the original scene it may be appropriate for an image to have a histogram that resembles an under or over exposed image.

6 Introduction to Photography and the Digital Darkroom by Edie Bresler 51 Brightness/Contrast is another adjustment layer that is useful for masks and small fixes, such as brightening the overall look of a print. Make adjustments to either the brightness or contrast (or both) by moving the sliders left or right. To move up by increments of ten click inside the window and use the up arrow key while holding down the shift key. Likewise you can decrease by 10-stop increments by using the down arrow key and holding down the shift key.