Image Tonality and the Histogram- Part Five: Output Levels and Internal Contrast

Graph vs Index HistogramThe Input Gives and the Output Takes Away

If you’ve wondered what the Output Levels are all about, here’s some insights. While the Input Black slider makes the Shadow Point darker and the White slider makes the Highlight Point lighter, their counterpart Output sliders (located below them in the Levels Adjustment panel) do just the opposite. The Output Black slider always makes all dark tones lighter and the Output White slider only makes all light tones darker.

The Input sliders build contrast while the Output sliders flatten contrast. The only obvious purpose in using the Output sliders is to lighten the Shadow Point and three-quarter tones and/or to darken the Highlight Point and quarter tones. While these Output sliders do change the Shadow Point and Highlight Point, they also adversely affect the internal contrast in a quite inarticulate and clumsy manner. To my view they are for the most part useless, as there are much more effective ways to shape an image’s internal contrast ; case in point, the Shadows/Highlights panel.

Shadows-HighlightsThe Shadows/Highlights Panel-

The Shadows/Highlights panel (Image/Adjustments/Shadows/Highlights…) adjusts the tonal range from an internal contrast perspective. The Shadows/Highlights panel does not alter the Shadow or Highlight Points; it rearranges the values in three-quarter tones and quartones respectively. The multi-adjustment sliders in this tool actually affect the three ranges of an image; three-quarter tones, midtones, and quarter tones, and they do so in a totally interactive manner.

Moving the Highlights/Amount slider to the right, for example, affects the internal contrast within the quarter tones without changing the Highlight point itself. This adjustment separates the Shadow point from the next darkest tones in the image. In the same way, the Shadows/Amount slider lightens the three-quarter tones without changing the actual Shadow point itself. This slider establishes the internal contrast in the darkest tones of the image.

The Midtone Contrast slider shifts the tones darker or lighter around the midtone point.

SpiralStaircaseBWThe Shadows/Highlights panel is one of the most powerful tools in the entire software editing arsenal because it affords control over all three critical areas of the tonal range that determine detail and clarity. The visual choreography of these adjustments gives you amazing lattitude in shaping the overall internal contrast of the image. When the Shadows/Highlights controls are coordinated with the three control points of the Levels dialog, the tonal reproduction range is under your control.

The interaction between the Levels panel and the Shadows/Highlights panel control the entire tonal range of the image.

The sixth (and last) post in this series will address the integration and interaction of all three tone range points and all three internal contrast regions. Stay tuned.

This series is a small excerpt from my soon to be released book titled The Digital Image: From Capture to Presentation and Everywhere In-between. If you find this series helpful, I encourage you to watch for the more comprehensive book.

Anyway, that’s the way eye sees it. Feel free to leave a comment and keep the conversation going. If you saw this post listed on a LI group page, add a comment to the listing in that group! Thanks for joining me. If you like this blog, let me know and tell your friends.

This is the fifth entry of the spooky series called Image Tonality and the Histogram. This series is open to the public but I highly recommend that you join the followers of this blog to keep the flow intact. Sign in now as a follower (top right of this page).

See you next time, Herb

Click the Follow button at the top of the page so you don’t miss any future posts.

AC AVTB CoverPS. if you have an iPad and are interested in learning about more about the fundamentals of digital photography, I suggest that you take a look at my Accurate Color iBook in the iTunes Store

About Herb Paynter

Herb is a published author, photographer, retoucher, color reproduction specialist and a regular writer for Digital Photography School. Download his iBook "Digital Color Photography: A Deeper Look" from the iTunes store and view his Light and Color Fundamentals video series at
This entry was posted in Tonality and Appearance, Underpinnings and Core Issues and tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , . Bookmark the permalink.

6 Responses to Image Tonality and the Histogram- Part Five: Output Levels and Internal Contrast

  1. Galen says:

    Simply put i enjoyed reading your ultimate web site
    and additionally a feeling. You were surprising.
    A big heads up with regard to advertisment this particular when i desire to
    research considerably more of one’s stuff definitely.
    Perfect chore trying to keep your internet site clean or high quality without having nearly every spammy posts.

    Does someone experience any helpful hints to my very own blog page to help they totally free from spammy posts?
    And also suggestions to create that includes extraordinary high-quality the same as your own property?
    Hi for my speech 🙂 genuinely as opposed to a few originaire phrases, have high hopes one can realise

  2. Right here is the perfect website for anyone who wishes to understand this topic.
    You understand so much its almost hard to argue with you (not
    that I actually will need to…HaHa). You definitely
    put a brand new spin on a topic that has been discussed for
    many years. Great stuff, just great!

    • Herb Paynter says:

      I’m glad you found this topic interesting. As a result of the various responses I received (some I approved and some some of which I didn’t), I have just introduced an image optimization service (called ImageOpt I’m betting that low price, good work, and timely service, that some of the marketing-minded agents will take advantage of ImageOpt. Thanks for the kind words. I actually viewed your blog and found it quite insightful.

  3. says:

    I have read so many posts on the topic of the blogger lovers however
    this piece of writing is genuinely a pleasant article, keep it up.

  4. Alfred says:

    whoah this weblog is magnificent i like studying your posts.
    Stay uup thee grewt work! You recognize, lots of individuals arre looking around for this info, you couhld help them greatly.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s