The Perfect Photoshop Elements Workflow – Part 1, Reading a Histogram

Reading a Histogram in Photoshop Elements

Getting the correct lighting and exposure is critical to taking a great picture.  The Levels histogram is a tool provided by PSE to let you analyze and adjust the distribution of the pixels in your image among shadows, midtones and highlights.  Adjusting the levels of pixels among these areas is a good way to improve a poorly exposed photo.

Very technical photographers and Photoshop users will tell you that Levels doesn’t actually correct exposure.  But we don’t care about what’s happening technically, right?  Levels can help you!

Here is the histogram from the Levels Adjustment Dialogue box in Photoshop Elements:

The shadows in my picture are represented by the left third of the graph, above the Black Slider.  The highlights are represented by the right third, above the White Slider.  And the midtones are, of course, in the middle.  The higher the black peaks in the graph, the more pixels are concentrated in that tonal range.

The Levels Adjustment (explained in the next post in this series) will align the distribution of pixels based on your assignment of a black point, which identifies the shadows for PSE and a white point, which identifies the highlights.  Colors are adjusted based on these black and white points.  You can also assign a gray point to further refine your image.

So, I know at a glance that the picture associated with this histogram is just a tad underexposed.  I know this because most of the black curve is concentrated to the left of the mid-point, and there are very few highlight pixels.  Now, there are some pictures where this shadow concentration would be ideal.  But for many pictures, it’s a good idea to have pixels distributed more evenly across the shadows, midtones and highlights.

So what does all this mean?  How do you use it to improve a picture?  Well, this is enough boring and technical info for one day!  The next installment in this series will demonstrate how to use levels (and a couple of other methods) to improving brightness, lighting, exposure and color tone in an image.

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