Thursday, May 21, 2009

5 easy steps to better color using Photoshop

How can you get better color in a digital photo?

Take its temperature!

If you make only one change to improve the color of your photos it should be to correct the color temperature of your image. "Color temperature"—also known as "white balance"—refers to the number of kelvins (K) emitted by a given light source. A 40-watt incandescent light bulb, for example, is 2650K, whereas a camera's flash might be around 5600K. The higher numbers have more blue and the lower numbers have more red. In practical terms, this means that if your photo's white balance setting (temperature) is at odds with the temperature of the light source, your colors will suffer.

Let's look at an example:
Cute kid. Bad white balance.

The easiest way to assess a white balance problem is to look for something that should be white, such as that t-shirt.

Question: What color is that triangle of "white?"

If your answer was "white," your eyes are playing tricks on you. Your eyes are so good at adapting to all kinds of color conditions that you need to train them to look at things more objectively. So just to check our perception, let's use the color picker and sample that tee-shirt for our answer. The sampler can have variations as I have described in another post, but it will help make a point nonetheless.

I click on the tee-shirt and see that our "white" tee-shirt is really....

Ugh! Blue! It looks as if the shirt were washed in hot water with a cornflower blue crayon.

So how do we fix it?

With a typical point and shoot camera, you might prevent the problem in the first place by using the proper white balance settings (as described in this excellent article). But I won't dwell on prevention here because

1. you can only expect so much of a preset white balance and
2. if you have a camera that shoots RAW (and if you do, I hope you are using RAW), a preset balance is less relevant.

If you shoot RAW...
you probably already know how to fix color, but let me illustrate how easy it is to fix RAW images in hopes of convincing those of you who have RAW capability to start using it. And by the way, more and more of the nicer point and shoot cameras have RAW capability, so next time you're in the market for one, get a camera that shoots RAW.

When you open a RAW image file in Photoshop, you get a host of adjustment sliders (and that's just the beginning). Once you know what the sliders mean, the rest is easy. Seconds later and...

massive change! If you look at the sliders, you can see that I changed the temperature, moved the tint further away from green, and did a few other minor changes that got fast results. The original image looks like it was salvaged from a bag of charcoal by comparison.

If you don't shoot RAW...
you can still get great results. Let me preface this section by reminding you that I prefer shorter and more intuitive solutions over time-intensive processes even if that latter might win over the approval of pro retouchers.

To my surprise, even a very user-friendly book that I love has a 19-step process for getting better color. Seriously. 19 steps! I mean, that's 7 steps more than it takes to reform an alcoholic!

My goal is to show you that you don't need to be a pro to improve your photos. In 4 or 5 steps you can take control of color in your photos.

The tutorial

Step 1. Add a curves adjustment layer.

If you have CS4, you can click on the curves adjustment layer button...
or if you don't (or if you have something against that button), get a curves layer from the bottom of the layers palette:
Our next three steps are going to use the black, gray (neutral), and white eyedroppers you see in the curves layer dialog box.
Step 2. Use the black eyedropper to click on something black (or as close to black as possible) in your image.
There are more precise and mathematical ways to do this, but we're not going to use them here. Among the blackest parts of this photo are the pupils, so I selected the black eyedropper and then clicked it in his right pupil.

The result is subtle so far. The color warmed up a bit and the photo got even darker.

Step 3. Repeat the process with the gray eyedropper.
This time you are looking for a neutral gray. I clicked on a neutral-looking part of the stone and here is what happened:

The skin tone looks less ashen, and things are getting brighter.

Step 4. Use the white eyedropper to select something that looks close to white.
I chose the tee-shirt and got the following result:

Depending on your monitor, this will either look too extreme or pretty good.

Step 5. Take it down a notch.
Unless you get really lucky, that white eyedropper might make a more drastic change than you desire. On my monitor, that post-white-eyedropper version looked way too intense, so I simply dialed the opacity of my curves layer down to about 47%.

Many a scary adjustment layer can be tamed by lowering the opacity. The lowered opacity means the boy no longer looks like he has been ingesting toxic waste.
The color temperature has been lowered because the original background layer is now partially showing through.

Step 5 (optional). At this point, you will either be satisfied or you will miss some of the brightness in the earlier version. Or maybe you want to tweak the skin tones a bit more or add more contrast. If so, simply add a new curves layer on top of your previous one (the one with the lowered opacity), and start tweaking. If you want to fine-tune the skin tone, you can adjust individual color channels (especially the blue and the green) as I explain in detail in one of my "starters." After you adjust the individual channels (if you do at all), you can boost brightness by dragging a point on the curve up and to the left, and/or if you want more contrast, you can create an "s" curve—all of which is included in the other tutorial.

I did some minimal tweaking for my final result.

Let's check out where 5 steps got us. Here is the "before":

and here is the "after":

If you can't leave well enough alone, you would probably bring out the eyes a little more, but I think any parent would be happy with the result we got in only five steps using curves.

2 comments:

Alexey said...

Simple metod, average result. For last page in home album :)

Add 2 masks, and adjust skin and cloth difference, then adjust background.
Finally we can increase foreground detail with USM.

Mikah said...

Thanks for the tip, using it right now!