Image Structure vs Sharpening vs Clarity?

[alecspra]

Hi! I was wondering what would be the equivalent of improving the "structure" of an image in AF? (Some NIK plugins for instance have a specific adjustment called "structure"). I am not really clear technically what it is that improving structure does to an image but it seems to be somewhat different from "sharpening". But maybe that is just my perception.

 

Here is an explanation about the differences between Clarity, Structure and Sharpening that I picked up on a photography website. I don't know if this explanation is correct but if it is, then improving Structure would require a somewhat different approach and possibly a different tool than improving Sharpening.

 

What are your thoughts on this?

 

 

"Consider an image of a tree and you have the option of using Clarity, Structure and Sharpening:

 

Clarity will enhance the tree trunk and the large branches  Structure will enhance the smaller branches and leaves.  Sharpening will enhance the structures on a leaf itself."

 

 

[Fixx]

Not sure tree example explains anything...

 

Sharpening looks for differences/contrast in areas next to each other and and enhances that contrast. That way borders get emphasized.

 

Clarity looks for micro contrast within areas and boosts texture. Think human skin in portraits -- it is bad idea to boost clarity as skin pores and imperfections will stand out.

 

Structure... now that one is hard...

[alecspra]

Thanks Fixx! Your explanation is much more useful than the tree example. It does sound from what you are saying that Clarity also boosts texture. As far as Structure is concerned, I have tried experimenting with Structure in Silver Efex Pro for example and I can see what it does but I can't quite figure out technically what it is. 

[gdenby]

I'm downloading Silver Efex Pro right now. Thanks for mentioning that. Always nice to have another tool set.

 

Here are some guesses about Clarity. Images that have a broad range of contrast are usually considered more visually attractive and interesting. If the overall contrast is limited, the image appears flatter. its harder to focus on any area because everything is too similar. So the overall look of and image will be improved if the range of darks and lights are expanded.

 

But,more important focal areas, the portions of an image that should be most evident, should have a high contrast. Think of a silhouette of a face profile. Just black and white. It is very simple, but enough to easily be recognized. In traditional drawing and painting, the most important forms are made to have a full range of contrast, perhaps higher levels of color saturation, and maybe a different hue or color temperature to separate the figure from the background. 

 

Structure and Sharpening apply the same principles at smaller scales. Depending on the image, too much structure and or sharpening can be a negative. There's and old maxim that goes "In art, less is more." Or another way, to use the earlier analogy, "Sometimes you can't see the forrest for the trees."

[alecspra]

Thanks for the input. Silver Efex is pretty cool but I think Google is no longer updating it so at some point it may become obsolete.