OverSharp Mask

[RichardC]

[doh] .........Hi Folks....... [doh]

After years of over sharpening my photo scans I?m finally going to ask if someone can help me. What is the best way to overcome the temptation to sharpen too much? Sometimes it looks fine on my screen but the print has ?..........?. It seems that I can?t trust my eyes when viewing the screen. Does anyone have a ?formula?? What is the best magnification to use when using UNSHARP MASK?
Thanks in advance......RC

 

[Welles]

Hi RichardC,

There are about a zillion sharpening techniques all of which have uses and drawbacks. Generally, I stay away from the Unsharp Mask and first try my favorite technique. Duplicate the background layer. On the copy run Filter > Other > High Pass... Adjust the Radius slider until you see the edges show up in the otherwise neutral gray preview. You don't really want to see much color, just shades of gray. Then change the blend mode to Overlay.

Russell Brown teaches a very clever technique for sharpening which I've never incorporated into my workflow and yet each time I think of it I wonder why not. Leave the background layer untouched. Duplicate it and run the Unsharp Mask on the copy. Exaggerate the unsharp mask action until you know it is just too much. Now, duplicate the layer you just sharpened. On one of the sharpened layers change the blend mode to Darken, on the other Lighten. You have just split the changed pixels from the sharpening process into two channels. You can dial up the relative sharpen by changing the opacity of those two layers and even take it further with layer masks to limit the areas affected.

 

[Sheba]

Hi richard,

I do a lot of work on photographs and I'm not saying this is the right way or the best way but it's definitely what I use 99% of the time.

I use the unsharp Mask at these settings:

Amount: 500%
Radius: 0.2 pixels
Threshold: 0 levels

Sometimes I will run it on it twice, depending what I am seeing. If it looks like twice is too much and once isn't enough, I will run it twice then go to Edit>Fade and change the opacity that way.

I also run an action on my images called *defog* which is the unsharp mask at these settings:

It cleans up the merky glow if you see it on certain images.

Amount: 20%
Radius: 60 pixels
Threshold: 0 levels

I usually do this one when I first start working on the picture and still run the unsharp mask at the end.

I never use the other sharpen options in the Filters, they definitely oversharpen images.

Hope that helps!

 

[Welles]

I'm definitely going to try your .2 radius at 500%, Sheba (and your other suggestion too, for that matter). Those are interesting approaches and I've not hear either before. No substitute for experience. (I actually do comparatively little photograph work.)

 

[RichardC]

Sheba......that's close to what I've been doing on my 300/400 PPI images but it seems too much (500%) on lower res images [doh] ...duh....

Do you use any particular zoom factor to see it best?

Thanks for the "defog" tip...I'll try that later.


Welles........Thanks for your suggestions. That should take care of the rest of the day for me [excited].....RC

 

[Sheba]

On the lower rez images, I would play with the slider on the Amount before playing with the Radius. I just opened a low rez image to see and I had the Amount slider pulled all the way down to 176% before it started looking right.

I always refer to the window in the unsharp mask rather than the image itself. I click on the image in the unsharp mask window to get a quick 'before and after'. And I always focus on a main part of the image, like the eyes, to get an idea of how it will sharpen.

Hope that helps too.

 

[RichardC]

I always refer to the window in the unsharp mask rather than the image itself. I click on the image in the unsharp mask window to get a quick 'before and after'. And I always focus on a main part of the image, like the eyes, to get an idea of how it will sharpen.

Hope that helps too.

You're helping! I didn't know a clic on the image in the mask window would do that......thanks.......RC

 

[Sheba]

You're welcome, Richard! This forum has helped me fine tune my PS skills greatly, I'm always willing to help in the few techniques I know about. :}

 

[Sark]

Just a variation of Welles method that might interest you.

Rather than duplicate the image. Run High pass at about 5pix or higher, on your image. Then go into Edit/Fade High Pass. Set blend to Overlay (Soft light for a less harsh effect). The Opacity slider now gives you a live preview that you can adjust to suit.

The High pass method give better results on photo images in my view, but the Edit/Fade command can also be used with Unsharp mask. By changing to Lighten, or Darken mode, it well effect the lighter, or darker areas more significantly. And again, you can control the extent of the effect using the slider.

Sark

 

[Sheba]

Sark!! That's an awesome technique! I just tried it and was blown away with the results!

8)) Hats off to you for explaining that so clearly! I just love learning new things.

 

[RichardC]

[excited] Wow Sark! That goes for me too. All these methods are pretty cool and fun too. Thanks all!.....RC