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Photography Question 
Ken Henry
 

High Pass Sharpening Technique


Which sharpening techique do you all prefer? The High Pass Technique or UnSharp Mask?


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11/6/2007 11:43:52 AM

 
William Schuette
BetterPhoto Member Since: 9/8/2006
  Hi Ken,
It depends on the the nature of the picture. Unsharp mask enhances the contrast on edges, High Pass tends to enhance the contrast of surfaces. So I use USM where I want a lot of fine detail, and HP when I want a surface to pop out from the background. A classic scenario for High Pass sharpening is a flower against an unfocused background. HP can really get the flower to pop out from the background. Also play with using both. Use USM first, but don't sharpen as aggressively as you might otherwise. Then add a High Pass on a separate layer so you can play with the blending modes and opacity. I have found that overlay, soft light and luminosity blending modes tend to work best. Hope this helps.
Bill


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11/6/2007 3:46:58 PM

 
Oliver Anderson
BetterPhoto Member Since: 11/16/2004
  I'm with Will on this one. You gotta practice and learn what works for you. Its been a KEY element to producing great images that only 3 people enjoy....thanks Dad.JK The size of your photo is definately related to the amount you'll be able to sharpen...thats why I always bought the same camera the photogs I worked with were using. the sharpening techniques will vary on your style and subject matter....I've assisted a few of the nations top photogs (in my area of interest) enough that we worked post production on photos....we ALL had different techniques...


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11/6/2007 5:07:28 PM

 
Ken Henry   Thank you Bill and Oliver. I just picked up on this High Pass Technique at Shutterbug. It's different. Your imput is very helpful.
My work is for Architects, Designers and other building trades. Lots of detail and texture and low contrast requirements. So I am using Reala film scanned at 24mpxl 16bit for a total of 125MBs. The D5 for more smoother subjects. Yup, large files for large photos.

Thank you again for giving me some of your techniques. This will help to direct me to practice samples easier.

Your galleries have really fine, superb photos Bill and Oliver. I can see that Your achievements require lots of practice and figuering it out.


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11/6/2007 6:28:51 PM

 
Richard Lynch
BetterPhoto Member Since: 6/12/2005
  There are quite a few different types of sharpening techniques, and most work by increasing local contrast. I have my own versions of manual sharpening that are more closely related to the darkroom version of unsharp mask which actually work by decreasing global contrast. This can come in handy on images where the image is already contrasty, and can be used successfully in combination with other methods of sharpening. I teach it in my course Leveraging Layers: Photoshop's Most Powerful Tool
The High Pass method, for those who don't know:
1. Duplicate your flattened background (I have to assume a flattened image to keep the instructions simple - you don't always have to flatten). Name the layer High Pass.
2. Run the High Pass filter (Filter>Other>High Pass). You will increase the Radius based on the size and detail in the image.
3. Set the High Pass layer to Overlay mode by selecting if on the Layers palette.
This will increase contrast on the image edges and enhance the sharpness. "Enhance" is a key word as you can't really sharpen a blurry image with success. Sharp images are best for sharpening!
Hope that helps!


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11/6/2007 7:24:59 PM

 
Susan J. Allen
BetterPhoto Member Since: 8/20/2005
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  I had never heard of or noticed the high pass function and just tried it on an image with incredible results! Thank you! Learn more every day at BetterPhoto!

One technique that someone taught me and that I have been using is using smart sharpen in Lab colour while lightness is selected in channels on a layer via copy. Could you explain how this compares with the other two techniques and in what situations it would be preferable (or not) to use?


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11/13/2007 4:25:46 AM

 
Richard Lynch
BetterPhoto Member Since: 6/12/2005
  Luminosity sharpening is another one of many techniques used for sharpening. The idea is that you sharpen tone/brightness only, and don't sharpen the color (or color channels) which can cause color abberation. You can do this as you suggest in LAB mode, or you can create a luminosity layer and sharpen that -- without switching color modes.

To do that you can:

1. Create a new, blank layer at the top of your layer stack.
2. Stamp Visible to the layer (Command+Option+Shift+E / Ctrl+alt+Shift+E [Mac / PC]).
3. Create a new layer above the previous.
4. Fill with gray (50% gray)
5. Set the mode of this layer to Color. It will turn the image black-and-white.
6. Merge down (press Command+E / Ctrl+E).
7. Name the merged layer Luminosity.
8. Set the layer mode to Luminosity.
9. Apply the Unsharp Mask filter to the Luminosity layer.

What you are doing here is making a composite of what is in your image (1-2), extracting the tone (3-8), and once you have isolated the tone in its own layer, you are applying sharpening to affect the tone only.

I don't go through this specifically in the Leveraging Layers course, but we get into this type of complexity. We also discuss separations of various sort that can pose other advantages. In essence, this will be the same as your Luminosity sharpening in LAB mode, but it keeps you from flip-flopping color modes which can complicate corrections.

I hope that helps!

Richard


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11/13/2007 11:15:58 AM

 
Oliver Anderson
BetterPhoto Member Since: 11/16/2004
  I believe the High Pass is used with Astromers as the favored sharpening method of Alien Watchers.Saw it on XFiles once.


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11/13/2007 12:11:48 PM

 
Justin G.
BetterPhoto Member Since: 7/13/2004
  Hey Ken this isn't an exact answer to your post but is a great article on sharpening.

http://www.creativepro.com/story/feature/20357.html

It also describes the luminosity sharpening that Richard described.

Richard, I've never seen it done that way, the way the article explains is a lot more complicated to the average person. I will definitely try your method!

Hope the article helps everyone!


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11/13/2007 7:00:24 PM

 
Ken Smith
BetterPhoto Member Since: 6/11/2005
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  Richard, thanks for explaining these two versions of sharpening!


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11/13/2007 7:12:47 PM

 
Richard Lynch
BetterPhoto Member Since: 6/12/2005
  Well, I can explain all the things that Mr. Fraser goes through there, and as you get more advanced these may make a difference for controlling your sharpening. I respect his work and interest in detail, and it is worth making the effort to understand -- though you may not need to work with that much tweaking in most images.

Keep in mind this luminosity method is one of many...meant for images that can stand a small increase in contrast. other methods decrease contrast, work on edges only, etc. Knowing a variety can help.

Richard


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11/13/2007 7:23:43 PM

 
Justin G.
BetterPhoto Member Since: 7/13/2004
  I've tried your method and it's way easier Richard. Thanks!


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11/13/2007 7:31:21 PM

 
Justin G.
BetterPhoto Member Since: 7/13/2004
  Oh wow I just discovered something. Well an article mentioned it so I tried it. Ok here's what you do.

1. Make another layer (do this in case you want to remove the effect later)

2. Go to Filter > Sharpen > Unsharp Mask

3. Keep the Amount at 10-20%

4. Take the Radius between 200-300 pixels.

5. Keep the Threshold at 0 levels.

This technique isn't actually for sharpening but it's great for contrast. And personally (situation depending) it seems like it has a more pleasing effect than the contrast tool.

Just thought I'd throw that out there!


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11/13/2007 7:57:05 PM

 
Christine Czernin
BetterPhoto Member Since: 1/6/2006
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  Richard, I just tried your luminosity layer technique on a picture of my (grown up) daughter. She'll kill me if she sees this! It DOES bring out the wrinkles.

So, now we know how the marketeers do the before and after ads for "anti-aging" miracle creams!!!


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11/13/2007 11:42:03 PM

 
William Schuette
BetterPhoto Member Since: 9/8/2006
  Justin, what you just discovered is that sharpening is just an increast in local conmtrast. By increasing the radius you turned it from a local adjustment to a more global adjustment of contrast.

Bill


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11/14/2007 4:12:08 AM

 
Stephanie Frey
BetterPhoto Member Since: 7/31/2007
  I have been learning so much with this thread. Just wanted to mark it so that I can keep up with it. Thanks a million!


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11/14/2007 5:21:09 AM

 
Ken Henry   Wow! You all have been helpful. Sharpening can go in many directions.

Justin, What you have found is called Pearlizing(by Dr Jalepeno from www.popphoto.com). The settings you have used may be extreme, I haven't gone that far, But I'll try it.

The basic setting guideline would be these examples: 30amount, 60radius. This of course is high enough to blow out detail in highlights. And that's on 24mpxl photos.
Usually I work with pearl settings at about 15a/30r then make ajustments up or down from there from there. One photo I had to Lasso out some white flowers because the petals were getting blown out.

I have tried combining High Pass and USM with good results, of course use lower settings. Pixlation was a lot lower.

I'll have to try out this Luminosity Sharpening technique Richard has here.
I only have Elements 5.

Thank's Justin for letting us know that Richard's method is easier.


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11/14/2007 9:45:34 AM

 
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