Avoiding Post-Processing Mistakes – Local Contrast Enhancement Halos


NOTE: The text below is currently lacking image examples. These will be added very soon. Until then, please watch the video for examples.

Recently I was doing free nature photography portfolio reviews for some of my audience members, and I noticed a specific post-processing issue in some of their images that’s really common. The issue is related to Local Contrast Enhancement, or LCE, which I’ll explain in this article. I’ve seen the same mistake in many other people’s photos online and so I decided to make a video and article about it.

I’ll explain what the issue is, why it occurs, and how to avoid it.

If you follow the instructions I give in this video, your photos are going to look a lot more professional, and you’re going to step above the average photographer and become more refined in your editing.

What is Local Contrast Enhancement?

Basically, Local Contrast Enhancement increases contrast in medium-sized local areas of the image, without dramatically affecting global contrast. This can create a slightly three-dimensional look with more apparent depth.

In Adobe Lightroom, the Clarity slider is basically LCE.

In Photoshop, LCE is a custom process you can do with a variety of techniques and adjustments.

If you want more in-depth information and techniques for applying LCE, you can watch my LCE tutorial video.

What’s the problem with LCE?

The specific issue I want to talk about today is that sometimes LCE can create unnatural halos.

I’ll show you this example. I have a bald eagle in flight image here, and I created a copy, and applied some LCE on it, and made it really dramatic so that you’ll see exactly what I’m talking about.

There’s a halo all around the subject. That’s not the only thing that’s wrong with this image in terms of LCE. Another thing that’s wrong is that this is a really contrasty, overdone amount of LCE (I turned it up really high, specifically to show the halo more dramatically). Disregard the fact that the actual subject looks too contrasty, and doesn’t look that good, and just pay attention to the halo

The other issues are covered in my tutorial about LCE so you can go watch that and learn more about it.

To understand why these halos appear, we have to know how LCE works.

The simplest explanation is that LCE increases contrast between adjacent light and dark tones in an image. And because these changes in contrast are constrained to a certain radius, it creates a halo

How do we fix this issue?

The answer is that you’re going to want to selectively apply LCE within the bounds of the subject, to hide the undesired change in tones that come outside of the subject, which is what creates the halos.

Example #1

I’m going to show you how to avoid the LCE halo issue.

Let’s use this killdeer portrait as our next example image.

I’m going to take all of my pixel edits that I have in a folder, and I’m going to merge them into a single layer so that I can then run the LCE on it. I’m going to highlight my folder that has all my pixel edits in it, then I’m going to hit Ctrl + Alt + E (Windows/PC) and that’s going to merge them into a single layer.

Then I’m going to run my LCE filter, that I have as a custom action in Photoshop that I created.

I have applied LCE to this layer.

Next, I’m going to make sure I have a selection that is precisely created for the subject (always make sure your selection is precise and accurate). I already have a selection made on this image, which I’m going to load.

Now I will apply a mask from that selection. I’m going to make sure that I’m on the LCE layer, which I just created, and I’m going to click the Mask icon, to create a mask out of this selection on to the LCE.

Now I have masked the LCE adjustment to within the bounds of the selection of the subject, which is containing those tone adjustments. Any tone adjustments from the LCE that would be showing outside of it are hidden, and therefore the halos are not showing.

You can see that applying a mask to the bounds of the subject is going to hide that halo, and your image is going to look more professional.

As mentioned earlier, if you’d like more information on LCE and how to actually do it, I have a tutorial.

Example #2

Let’s take a look at another example image, a geranium flower.

Same process, really easy. You’re going to take your pixel edits, and you’re going to merge them into a single layer. Then you’re going to run the LCE. Then you’ll load your subject selection. Next, make sure you’re on the LCE layer, and click the Mask icon. Then you’ll have a mask of the subject, which will contain the LCE within the bounds, so you won’t get any halo.

Example #3

There’s one more quick point I want to go over, and that is in some special cases you might need to tweak the application and the mask of the LCE. For example, if you have a reflection image, such as this one of this bird in the water, you’ll have to make the decision of: Do you want to apply the LCE also to the reflection, or just to the bird?

I applied LCE, and I have two examples.

The first one is applied just to the bird, and you can see the mask here of the bird.

The second one includes an additional selection of the bird reflection, and you can see there’s a little bit of LCE showing up in the reflection as well.

So, this is something to consider when you’re making your mask for the LCE application. If you do have a reflection like this, do you want to apply that there or not.

The advice I would give you is: 1. Just do whatever you think looks best, and, 2. The more clear and sharp the reflection is by default, the more you should apply the LCE to it. If instead it’s a very blurred out and indistinct reflection, then you would probably not want to apply LCE to it.

Just to briefly recap, in this tutorial we:

  • Learned that LCE, or Local Contrast Enhancement, is a way to give a photo more apparent depth and dimension.
  • Examined one very common post-processing mistake related to LCE, which is that it can create unnatural halos.
  • Learned that the solution to the issue is to constrain the LCE adjustment to the subject bounds by using a mask. Just create a selection of the subject and apply it as a mask to the LCE layer.

For a more in-depth look at LCE you can go ahead and watch my LCE tutorial video.

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By | 2020-11-10T07:52:54+00:00 April 1st, 2017|Categories: Post Processing, Tutorials, Videos|

About the Author:

I'm Matthew Schwartz, the founder of Nature Photography Mastery Academy™ I specialize in fine art nature and wildlife images. I spend much of my time learning new photography skills, techniques, and equipment, as well as developing further mastery of Photoshop. I am a member of the North American Nature Photography Association (NANPA), and several local Meetup Groups. View my photography on flickr