Photofinishing with Photoshop: Introduction to Contrast & Color

Copyright © John Watts

Suriname, South America

GET UPDATE INFORMATION for CS6/CC by clicking on the links.

Previously, I talked about the 8 basic elements of a good color print. During this session, I will cover the basics around Contrast and Color.

Updated information on contrast, brightnessa and hue and saturation.

Contrast

Why is this important? Proper contrast gives your image some “snap” and is pleasing to the eye.

As our eyes generally like “snappy” (higher contrast) prints, you should try to achieve the maximum “snap” or high contrast without blocking up shadow areas, while retaining detail in the highlight areas.

Contrast is defined as the range or relative difference between light and dark areas of an image. An increase in contrast results in less range and a decrease results in more range.

If your image lacks contrast, it looks thin and lifeless–your blacks are washed out and your highlights are dull. If your image has too much contrast, your highlights are washed out and your shadows are blocked up.

The easiest way to adjust your contrast in Photoshop is the “Brightness/Contrast” adjustment. However, it is too generic and does not give you much in the way of control.

There are 2 better choices to adjusting Contrast: Levels and Curves.

Levels

 
The Levels dialog box will let you correct the tonal range and color balance of an image. It will allow you to adjust the intensity levels of the images shadows, mid-tones and highlights. The Levels histogram is a visual guide for adjusting the image key tones (black point, gamma/midtone and white point).

Here’s a very simple way to increase your contrast using Levels.

Open a Levels adjustment layer in the Photoshop Menu Bar: Image > Adjustment > Levels and a “histogram” with various controls will pop up.

Underneath the histogram (Input Levels) are three triangles. Move the triangle on the left (the “Shadows” slider–black) to the right to increase the contrast in the shadow area. Move the middle triangle (the “Midtones” slider–gamma) to the left to decrease contrast and to the right to increase contrast. Move the triangle on the right (the “Highlights” slider–white) to the left to increase contrast. Be careful with the Highlights Slider– you don’t want to lose too much highlight detail!

Curves

The Curves dialog box will allow you to adjust the entire tonal range of an image. Where Levels only has the three point adjustments, Curves lets you adjust shadows to highlights, using up to 14 different points throughout an image’s tonal range.

Due the the complexity of the subject of Curves, we will cover this subject in the upcoming article. 


Color

“The color in my print doesn’t look right!”

How many of us have heard this from other photographers, or have said this about our own prints? Let’s go over some basics of Color. You will then be capable of making color corrections with more confidence and accuracy!

So what is Color? The dictionary defines it as the quality of an object or substance with respect to light reflected by the object, usually determined visually by measurement of hue, saturation, and brightness of the reflected light.

Now let’s expand on the definitions:
Hue is a single color cast or color name.
Saturation is the intensity or purity of a Hue.
Color correction is correcting an imbalance in the color cast(s) of an image.

Let’s also introduce you to the primary colors:
Red, Green and Blue and their corresponding opposite (complementary) colors are Cyan, Magenta, and Yellow.

A simple example of Color Correction:
To correct for an image with an overall blue cast, you would add it’s opposite (complimentary) color to bring the color balance back to where it needs to be. For instance, add Yellow to correct a Blue cast.

A very important tip:
When judging for proper color balance in your print, look for “neutrals”, such as white or grays. Let’s say you have an image of your house, which has white shutters. Look at the sidewalks (gray) or the shutters (white)–correct those and the rest of the overall color balance will typically fall into place.

Now let’s talk about the basic “tools” available in Photoshop to properly adjust your color. Like most Photoshop tools, keep in mind that these tools can be used “globally” (affects your whole print) or “locally” (affects a portion of your print, using selection tools).

Note: I’ve also found that the “generic tools” such as Brightness/Contrast or Color Balance are too global, simplistic or destructive to the image to be of any major use. Having some extra control will also create some challenges–there is quite a bit more complexity with Levels and Hue/Saturation. A good analogy is the difference between an automatic transmission and a manual transmission in an automobile. Both transmissions accomplish the same thing: you have much more control with a manual transmission, but with that control comes added complexity, such as shifting and clutch coordination, and so on. It takes a lot of work and practice to master them but, just like learning to drive a car with a stick shift, the results are well worth it.

1.) Hue/Saturation Adjustment Layer

Open a Hue/Saturation adjustment layer in the Photoshop Menu Bar:
Image > Adjustments > Hue/Saturation
and this box will pop up.

This should be the first basic “tool” you should use. You can adjust Hue, Saturation and Lightness by using a combination of the sliders and the drop-down menu. I rarely adjust the overall Hue/Saturation by editing the “Master”. I prefer the control of adjusting different hues by picking that hue in the drop down menu.

For example, you have yellow daisies in your image, and they are too orange and saturated. Pick “Yellow” in the drop-down menu, move the “Hue” slider slightly so your flowers are more yellow, and de-saturate by moving the “Saturation” slider. Don’t forget the “preview” check box to see your “before” and “after” changes.

2.) Photo Filter Adjustment Layer
This tool is great for correcting an overall color cast. It’s just like using a colored filter on your camera when shooting–adjusting the color balance and color temperature of the light transmitted through the lens.

Open the Photo Filter adjustment layer in the Photoshop Menu Bar:
Image > Adjustments > Photo Filter
and this box will pop up. 

Or…..

Choose Layer > New Adjustment Layer > Photo Filter. Click OK in the New Layer dialog box and a new layer will appear along with the box to the left.

You can choose the filter color by the use of either a custom filter or a preset filter from the Photo Filter dialog box.

For a preset filter, as you see selected here, select the Filter option. You’ll have a variety of choices from which to choose, from “Warming” colors to “Cooling” colors to an array of preset colors. 

To customize your filter, select the Color option. Just click the color square and you’ll be able to use the Adobe Color Picker to choose a color.

To adjust the amount of color applied to the image, use the Density slider or enter a percentage in the Density text box. A higher density results in a stronger color adjustment.

These, of course, are not the only ways to adjust your color, but these are proven in a commercial environment and should take care of most of your color correction needs without sacrificing control. As always, Photoshop’s “Help” section is an excellent source for the basics on how to use these tools.

Visit me next time, when we cover the subject of Contrast using Curves.

by John Watts

All written content (and most images) in these articles are copyrighted by the authors. Copyrighted material from Apogee Photo Mag should not be used elsewhere without seeking the authors permission.

Be the first to comment

Leave a Reply

Your email address will not be published.