I have been using Lightroom 4 for a while now and have already written extensively on the printing related issues. In this post I will bring to your attention a different kind of problem which is tied to the Clarity slider which is supposed to add “clarity” by making the features of the photograph crisper. In the most recent issue of Photoshop user magazine, the Lightroom guru Matt Kloskowski referred to the new slider as “Clarity Slider Rocks”. I beg to differ. I have written about this problem on Adobe Lightroom forum with several readers there chiming in, some favoring the new behavior others are either on the fence or in agreement with my assessment.

The clarity slider in Lightroom 3, using 2010 process engine had a range spanning -100 to +100. Moving the slider towards +100 added progressively more crispness, crunchiness to the image to the point that the image may start showing disturbing halos around the edges where dark met light. This point of diminishing returns depended on the image content and users adjusted the setting visually. While doing this, LR3 clarity did not alter the tonal balance of the image outside those edges present in the photographs such as a building roof meeting the sky, or tree branches against lighter background, even eyelashes and eyebrows in portraits without disturbing the tonal balance appreciably. The only problem to deal with was the halos and its behavior was well understood.

As I started using Lightroom 4 and its clarity slider, I noticed a markedly different behavior. Instead of limiting its area of influence to where there are edges like tree branches, or roof lines, the clarity slider in LR 4 was more aggressive. In an effort to reduce the halos that could appear in LR3 when the clarity slider was pushed a little too hard, the Adobe engineers seemed to have drastically altered the algorithm to affect an overall tonal change, as if tone mapping. The result is potentially significant tonal changes that can create either extra work or they are outright unwanted side effects. Proponents of the new clarity slider defend the new behavior as “more powerful and does not create halos”. They also add that, possibly because of this “power”, only half of the LR 3 clarity slider amount is necessary. But, I have not read, or heard on a podcast what this new power may be. The proponents also add that the new clarity slider need not be pushed beyond 20-25. Well, if it is twice as powerful, and the user needs only 20-25, why give the full range up to 100?

So, What’s The Problem?

I will share my reasonably controlled tests and point out the problems associated with the new clarity slider. Mind you, the behavior I will outline may not be visible on all images on which you use this adjustment, or you may be willing to live with that. But, that does not change the fact that the behavior of this slider is no longer limited to affecting the immediate surroundings of edges in the image and it does affect the tonal balance between the light and the dark in the image almost on a global basis. This means that you may go through the typical, and recommended, workflow of adjusting the white balance, correcting exposure and contrast, handling blown highlights and blocked shadows, then add some “clarity” only to find that your carefully adjusted tonal balance needs to be revisited. To top it all, you will have to go back to tonal adjustments every time you make changes to the clarity slider. That is not productive in my opinion.

Evidence: It’s not better in “clarity” but worse in “tonality”

Here are four images processed in LR 2010 and 2012 settings using only the clarity slider, there are no other adjustments made to the image.

These are the comparison photographs, you will see in the next row direct comparisons.

The following are the half-and-half comparisons. The dividing line is a diagonal that goes through the axis, from the gondola to the the top of the balloon, you will see it clearly in the LR4 comparison photos. I would like you to observe several things:

1. LR 3 and LR4 images with no clarity are practically identical, so the starting points are the same
2. LR 3 clarity at 50 produces crisper lines on the balloon without making the sky or the balloon darker or lighter appreciably
3. LR 4 clarity at 25 produces less crisp lines on the balloon at this setting yet both the sky and the balloon surfaces are changed in tonality

Now, the clarity not being any better in LR4, in fact I find the LR3′s added clarity at 50 better than LR4′s at 25. You may say, “increase the LR4 clarity to a higher level” but that also increases the additional tonal shifts. Here are some more examples with more aggressive adjustments.

In the image on the left, you see the baseline image on the left, LR 3 aggressive adjustment with clarity at 100, and on the right LR 4 clarity at 50. Take a look at the sky at the top edge of the photograph. In the LR3, 2010 engine clarity, there is no difference in the sky tone as it should be. Now take a look at the darkened tone of the sky with the LR4 2012 engine clarity. I did not make the sky darker, why should clarity do that for me? Also noted that LR3 with clarity at 100 is really an extreme adjustment where in LR 4 leaves more room to push it, with more undesirable results.

Let’s see what happens if we push them both.

In the following images of fruits in a white bowl, I pushed the adjustments to their end points. In sequence, you will see unadjusted image, LR 3 Clarity=100, LR 4 Clarity=100, and LR 4 Clarity=50.

See how muddy the third and the fourth images are. Take a look at the rim of the bowl, the highlight is practically gone where one would expect the opposite effect. Also view the inside of the rim of the white bowl, it now has something akin to soot being smeared on it. This look appeals to some users as the “grunge look” but it should not be a side effect of an adjustment that purports to enhance the clarity of the image. There are other ways of getting this result INTENTIONALLY. Adobe evangelist Julieanne Kost refers to this behavior as “faux HDR look” in her presentation on Adobe TV. She is spot on, the clarity slider has been redefined as “faux HDR look” slider, and for that it works well. But let’s call a spade a spade!

Here are some more examples provided by another Lightroom user who is also dissatisfied with the new clarity adjustment. You can clearly see the change in the tonal structure and the photo becomes progressively more “faux HDR look” style. (Images are used with permission.)

My conclusion

Improving the halo prevention on the clarity slider has produced unexpected, and in my case unwanted, side effects. The intended purpose of the clarity slider has been to add “crispness” to the image by adding contrast around the edges visible in the photograph. Before Lightroom came into the picture, and before even Raw Shooter was a player, we used to use either a large radius-low amount sharpening or high pass sharpening with a modest radius for this purpose.

The new clarity has turned into a tool which up to a point works the way it used to, beyond that it acts like a light-weight tone mapping tool with no additional controls. That, in my opinion renders it less useful as its behavior cannot be predicted. The best way to describe how it feels to use this tool is to liken it to a tool that tries to get out of focus areas into focus (refocus?) at the expense of parts that are already in focus. If you have a photograph that has atmospheric haze, or shot through a foggy window you may like this tool. If on the other hand, you have a photograph where the parts you want in focus are already in focus, you will probably be disappointed with the new clarity adjustment. This is probably a broad generalization but after you try it on photographs that show these traits you will probably see what I am trying to convey, with my words as well as with the image examples I have provided.

My recommendation

I suggest, with due respect to those who like the current clarity slider, that Adobe add at least a check box next to the clarity slider that alters its behavior to 2010 engine on a per image basis. That will keep both camps happy. There are precedents for this in Photoshop, the most recent one being in the crop tool menu. Otherwise, this tool ,for my purposes, is unpredictable and broken. I have to find other ways of dealing with the clarity issues.

I welcome your comments on either side of the discussion and will approve all comments that speak to the issue.