Luminous Landscape Forum

Raw & Post Processing, Printing => Other Raw Converters => Topic started by: Ken Alexander on April 23, 2008, 07:33:20 pm

Title: Adjust | Focus | Highpass
Post by: Ken Alexander on April 23, 2008, 07:33:20 pm
Very nice to see a Capture NX forum...thank you!

I use NX to do a few things that I couldn't do with Aperture, although that has changed somewhat lately with 2.0.1.

Anyway, I understand that Adjust | Focus | Highpass has to do with sharpening, but I find the NX manual lacking in this area.  I see what highpass does when I select it, but what's next?  How do I apply it t improve the image I'm working on?

Thanks in advance.

Ken
Title: Adjust | Focus | Highpass
Post by: Daniel Arnaldi on April 23, 2008, 08:43:22 pm
I don't have NX on this computer to confirm this so what I'm writing now is based on some experimenting I did some time ago.

Using High pass to sharpen with in NX is similar to PS, you need to change the blending option to "Hard Light" and then work with the opacity slider to adjust the degree of the affect.

You'll find there are several techniques that work the same in NX as in PS, I've often found that techniques that work in PS can be similarly applied in NX, not necessarily the same in practice but in concept it often does work the same.
Title: Adjust | Focus | Highpass
Post by: Daniel Arnaldi on April 24, 2008, 04:25:46 am
Correction! I said overlay before for the blending option, in fact it's Overlay
Title: Adjust | Focus | Highpass
Post by: ghervey on April 24, 2008, 01:01:58 pm
Quote
I see what highpass does when I select it, but what's next?  How do I apply it t improve the image I'm working on?

Thanks in advance.

Ken
[a href=\"index.php?act=findpost&pid=191507\"][{POST_SNAPBACK}][/a]

I use the High Pass filter for sharpening quite a bit.

Here is how I do it.  (Note that you only need to run through this routine one time.  When you are finished, save it as a Setting.)

Add a High Pass Filter to the image:  Adjust>Focus>High Pass

In the Edit List, open the Opacity controls for the High Pass edit (that is, click the Opacity triangle in the lower right of the High Pass edit step box).

Set the Opacity mixer to Luminance and Chrominance mode.

Set the Chrominance opacity to 0%

Set the Blending Mode to Overlay.  

Click OK in the Opacity dialog box.

Open the High Pass edit step (by clicking the triangle on the lower left side of the High Pass edit step box).  This brings up a Radius slider.  Move the slider left and right until you achieve the desired result.  

Note that you will probably get the best results (in my experience) for most images with a radius setting of between 0.8 and 2.0.  Anything more is going to look bad, in my opinion.  Images that are in good shape to begin with will probably not tolerate a Radius setting over about 1.2 or 1.3 before they start looking over-sharpened.

I generally use this sharpening technique later in the process, after I apply a gentle, global capture sharpening routine earlier in the workflow.  I also use High Pass to sharpen selected areas, especially eyes and other facial features that I want to stand out; once I apply the filter, I paint it in where I want it.  

As noted above, once you have gone through all of these steps, it would be a good idea to save that edit step as a Setting, which you can call up and use later.  Before doing that, however, I suggest that you move the radius slider to between 20 and 30 pixels (I set mine at 25) and then save it as a Setting.  That way, when you load the Setting later, it starts out really high.  Just open the High Pass edit step to bring up the Radius slider, and move the slider back down.  

My main source for this technique is RealWorld Nikon Capture NX by Ben Long, p. 188.
Title: Adjust | Focus | Highpass
Post by: Ken Alexander on April 24, 2008, 05:37:31 pm
Quote
I don't have NX on this computer to confirm this so what I'm writing now is based on some experimenting I did some time ago.

Using High pass to sharpen with in NX is similar to PS, you need to change the blending option to "Hard Light" and then work with the opacity slider to adjust the degree of the affect.

You'll find there are several techniques that work the same in NX as in PS, I've often found that techniques that work in PS can be similarly applied in NX, not necessarily the same in practice but in concept it often does work the same.
[a href=\"index.php?act=findpost&pid=191519\"][{POST_SNAPBACK}][/a]

Thanks for your help, but I don't have Photoshop so any reference to it just goes in one eye and out the other.

The NX dialog box has a Blend Mode setting, but Hard Light isn't one of them.  I suspect you're speaking "PSese" and not "NXese".  I don't speak either very well, but if we can continue in NXese then we'll ultimately do better.

Thanks again,

Ken
Title: Adjust | Focus | Highpass
Post by: ghervey on April 24, 2008, 05:46:42 pm
Quote
I don't speak either very well, but if we can continue in NXese then we'll ultimately do better.

[a href=\"index.php?act=findpost&pid=191682\"][{POST_SNAPBACK}][/a]

See NXese explanation I posted earlier (I even translated it into English!)
Title: Adjust | Focus | Highpass
Post by: Daniel Arnaldi on April 25, 2008, 01:18:46 am
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Set the Chrominance opacity to 0%

[a href=\"index.php?act=findpost&pid=191632\"][{POST_SNAPBACK}][/a]

Good suggestion but I would add a caution of setting the Chrominance opacity to 0% as rule as some edges are not as clearly defined by luminance as they are by color, and keep in mind that most of the noise in NEFs is in the Luminance channels so turning off the Chrominance channel will not have the same benefit for NEFs as it does for other file types.
Title: Adjust | Focus | Highpass
Post by: ghervey on April 25, 2008, 05:53:31 am
Quote
Good suggestion but I would add a caution of setting the Chrominance opacity to 0% as rule as some edges are not as clearly defined by luminance as they are by color, and keep in mind that most of the noise in NEFs is in the Luminance channels so turning off the Chrominance channel will not have the same benefit for NEFs as it does for other file types.
[a href=\"index.php?act=findpost&pid=191779\"][{POST_SNAPBACK}][/a]

Very nice tip.  Thanks.
Title: Adjust | Focus | Highpass
Post by: Ken Alexander on April 25, 2008, 09:08:28 pm
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See NXese explanation I posted earlier (I even translated it into English!)
[a href=\"index.php?act=findpost&pid=191684\"][{POST_SNAPBACK}][/a]

Now THAT I understand, and have since tried, successfully.  Now to go back and read when to use it.

Thank you!

Ken