PI8 Photo Editing With Levels
Photo editing enthusiasts are bound to appreciate the power of PI8's new Level command. Level helps you fix photos that are too light or too dark by adjusting the darkest and lightest pixels within an image to black and white. This redistribution, or shifting of colors, can salvage photos that are too dark or too light, and create artistic effects for merely acceptable photos.
I'll be using one of my less than perfect vacation photos to illustrate this tutorial, this one taken at the lost colony of Jamestown. You can right click and save it to follow along.
I was standing out in the bright sunlight taking this shot of my family inside an indian hut, where it was very dark. The only available light was dim and golden, coming from the doorway. It's one of my favorite photos from our trip there, but you can barely see their faces.
Open up the image and hit Ctrl+D to duplicate it. We'll be trying two different Level techniques for lightening up this photo. Then you can compare the two methods to see which one you think looks better.
Choose Format, Level to open the Level dialog box. A histogram shows the current distribution of tones in the image. As you can see in the screen shot below, the colors in this photo are weighted far too heavily on the dark end of the distribution.
The little triangles are anchors which you can drag to adjust black (left), white (right) and gamma (middle) values. Like most of PI's dialog boxes, you can edit the Master channel, or the Red, Green or Blue channel selectively. You can also click directly on the Before image in the left window with the Eyedroppers to define black, white and gray within the image, thus shifting the color distribution.
Equalize is a good place to start for images like this one that are too dark, because it redistributes the brightness values within the photo. Click Equalize and look in the Preview window. Yikes, it looks terrible, doesn't it? The Equalize option lightens too much and bleaches the whole photo out. To get rid of that effect, click Reset.
Another possibility is to drag left on the right (white) anchor to adjust the lighter tones. Drag it left to make the value=175.
You'll see how much brighter the people look in the right preview window. Click OK to accept the edit. Notice how much better the photo looks? Not only is it lighter and with better contrast, but the gold light suffuses the entire photo. The walls of the hut are a warm, reddish color.
Let's try another way of using Level to edit the same photo. Click on the blue title bar of the other, unedited photo to make it active. Choose Format, Level. This time when the dialog box opens, note the Stretch button. Stretch literally stretches the range of tones in the image by identifying the black and white points, then redistributing the rest of the colors within that range. You can click Options to redefine the Stretch range, specifying the percentage of shadow and highlights to be included when the command is performed.
Choose the Stretch option and watch its effect on the histogram.
Better yet, click Preview to view the effect of Stretch on the full size image. Click Undo and Redo a few times to see the benefits of Stretching the Levels. End with Redo and click Continue to return to the dialog box.
Note that after Stretch is applied, you can further tweak the settings by dragging on the histogram controls, if you wish to do so. I edited the white value to 245 to make the lighter tones slightly lighter after Stretch. Click OK to apply the effect. Here's the results.
I like this tweaked Stretch effect more than the first version. The background stays darker and less red looking, and the lighter colors look brighter to me.
This is, of course, one of the maxims of photo editing -- it is very subjective. Some of you may prefer the first edit because it is less bright and more warm looking. Now that you know how to experiment with the Level command, you're on your way to editing photos in a way that looks great to you.
This tutorial uploaded 11/1/02
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