Ask An Expert: Photoshop Unsharp Mask Vs. Lightroom’s Sharpening Tool

Today’s “Ask An Expert” question is an outstanding one.  I’d never given much thought to the difference in sharpening an image using unsharp mask in Photoshop vs. using the sharpening tool in Lightroom.  Apparently Nat Coalson hasn’t only given it a lot of thought, he’s developed some really solid logic behind why you should use Lightroom to sharpen your images.  Nat is an Adobe Certified Expert and the author of Lightroom 2: Streamlining Your Digital Photography Process.  He’s also co-leading our “Wildflowers and Reflections in the Tetons” workshop June 10 – 13, 2010.  Here’s the question I received and Nat’s thorough response.

The Question:

How does the sharpening in Adobe Lightroom compare to unsharp mask sharpening in PhotoShop. I have heard several people claim it is good to use for capture sharpening for images submitted to agencies that will be licensed by clients who will then resize and do additional output sharpening.

What is the difference in Lightroom sharpening and Unsharp mask??

Nat Coalson Responds:

The sharpening on Lightroom’s detail panel is very different from Photoshop’s Unsharp Mask.

Unsharp Mask was developed many years ago in the early days of digital imaging. Though it has been the de facto standard on which many other methods of sharpening are based, it’s crude in comparison to newer algorithms, and can produce destructive artifacts relatively easily.

On the other hand, Lightroom’s sharpening is designed to be “gentler” in it’s application, and will produce fewer haloes and other artifacts if used properly.

Modern sharpening workflows involve several steps of sharpening, unlike older techniques of the past, when it was believed that the optimal amount of sharpening could (and should) be done in a single pass.  These days, sharpening is broken down into three stages: capture, creative and output.

Capture sharpening overcomes the loss of sharpness resulting from the pixel grid itself. Every digital image capture suffers from some amount of softening as a result of the real, organic world being mapped to a discrete grid of pixels. The sharpening on the Detail panel is intended to be capture sharpening only and to simply overcome this inherent loss of sharpness.

Creative sharpening is used to enhance specific areas of the image.  Lightroom’s local adjustment brush provides the ability to “paint” on sharpening in localized areas.

Finally, output sharpening is applied when the file is Exported or printed. Output sharpening is applied using the appropriate method and strength for the inteded output destination. For example, if you’re printing to a matte fine art paper, you would apply more sharpening than if printing to a glossy coated paper.

My default settings for sharpening on the Detail panel:

Amount 60 > The strength of the sharpening to be applied.

Radius 1.1 > The width of the sharpening along the “edges” of contrast. For images with lots of fine detail, I might go down to .8 pixel radius, and increase the Amount. Images that don’t have lots of fine detail might go up to 2.0 radius, but never more than that.

Detail 50 > Similar to radius, if the photo has lots of fine detail, use higher levels of Detail.

Masking 15 > Masking restricts the application of sharpening from being applied to areas of smooth, solid color and limited contrast. For example, blue sky or the skin in a portrait usually should not be sharpened; masking keeps the sharpening from being applied to these areas.

For all the controls, holding the option or alt key while moving the slider will show you a grayscale preview of the effect being applied.

To see the sharpening previews on the image itself, you need to be zoomed in to 1:1 or greater.

I usually fine tune these settings on an image by image basis, but these settings will give me close to the ideal amount of sharpening to begin my processing, on the majority of images.

I often apply standard or high levels of output sharpening, too.  Though there’s not a lot of direct control over this in Lightroom, the levels of output sharpening they’ve included work pretty well, and are very simple to apply.

All of this is based on raw capture; if you shoot JPG then some sharpening is already applied in the camera, and the settings would be different. (But in the Lightroom workflow, there is no reason to ever shoot JPG!)

If you do as much of your work as possible in Lightroom, you may find that you never need to go into Photoshop, especially for sharpening.  Though there will be special cases and images that need the pixel-level editing that Photoshop provides, using Lightroom’s sharpening options properly may be all you need.

Share your techniques for sharpening in Lightroom and/or Photoshop in the comments below.  Someone just might learn something and that’ll send good karma your way.  We can all use a little extra good karma!

18 thoughts on “Ask An Expert: Photoshop Unsharp Mask Vs. Lightroom’s Sharpening Tool”

  1. I have tried these standard sharpening settings on several of my landscape images and have noticed that it almost causes a watercolor-painting look to the detail when you zoom to 100%. I am not completely sure this is what it is supposed to look like. When I am not zoomed to 100% it looks great though. Any suggestions?

  2. This is the best and most clear explanation I have read. I have found that Lightroom sharpening is great way to go for images that will be going to agencies/portals or my own website for downloading and licensing. Sicne there is no way of knowing how these will be used or at what size correct capture sharpening is critical.

    Allen Russell
    allenrussellphoto.com

    1. Allen: I’m glad you found Nat’s answer helpful. I learned a lot in reading his response. I had no idea what masking did until now. Guess I’ll be using it more going forward.

  3. Jim – the watercolor look you’re describing is likely caused by a combination of Amount and Radius settings being too high. In cases where you’re using high amounts (say, 50 or higher) you might need to use a smaller radius.

    Jackson – yes, ACR 5 and up has the same sharpening controls and algorithms as Lightroom 2.1 and higher.

    Lightroom 3 and ACR 6 will have new, improved sharpening algorithms.

  4. Very useful and informative. Thanks Bret and Nat. I have avoided using the sharpening algorithm in LR2 beyond it’s defaults due to the fact that I simply don’t fully understand it as well as I do with Photoshop’s Smart Sharpen…

    I remember reading somewhere that the default 25 amount in Lightroom that is applied whenever a RAW file is uploaded is the equivalent of 0… is that true?

    Thanks

    -Mac

  5. Mac – no, 25 is not zero. 0 is 0. To fully disable LR sharpening you need to use 0 for Amount.

    The sharpening defaults of 25, 1.0, 25, 0 can be overridden, too. If you have settings you like better, you can save them as a Develop preset and then apply them either on Import or from within the catalog. You can also save your own new global settings, in the Develop module under the Develop menu > Set Default Settings. Note that changing the defaults won’t affect any photos that you’ve already adjusted their settings; the default applies only to photos for which you haven’t changed those particular settings.

  6. hallo,
    thanks for these infos.
    i have a d300 camera with 35mm 1.8, 50mm 1.8, 70-200 2.8 and lot of 5.6 objectives.
    I think i am crazy because always look at 100% on my 22″ samsung t220 display at only 200usd. i have always the feeling that there is noise on nef (raw files) in lightroom.
    however, even with default of lr3.2 : 25,1,25,0 printing on 10×15 and 13×18 mm with standard sharpening is very good. i will try soon a4 210x297mm but i have a canon mp980 less good than epson r2880 and 5 cartdridges of 9ml is very expensive so a4 is not often.

    i process most of my images with capture nx2 and have fun with usm and highpass filter with u-points. however nx2 environment is slow, prehistoric, external slideshow with viewnx2…
    i try to switch from nx2 to lr3.2 but to be sure i keep my u-points (because find local brush with its masking not very powerful) i have purchased complete collection of nik plugins.

    I have lot of books of evening and scott kelby with examples and am very disapointed i can’t do same job in lr3.2 than with usm, lab mode and highpass filter with sometimes fusion masks. But reading posts like yours and others i discover than lr3.2 sharpening is not just a capture sharpening and I need to better understand sliders.

    all this discussion to say i am still learning detail panel but find a pity we can’t use as local adjustment.

    The big question never described on internet is local brush “clarity and sharpening sliders”. what are these ? how can we adjust sharpening with only one slider ? i suppose it is a gain slider so where are hidden radius and threshold ?

    kloskowsky, kelby,… all make capture sharpening with lr3.2 and switch to photoshop for creative sharpening. huumm strange…

    i miss a lr3.2 highpass filter …

    many thanks for advises
    best regards

    marc

  7. hallo,
    thanks for these infos.
    i have a d300 camera with 35mm 1.8, 50mm 1.8, 70-200 2.8 and lot of 5.6 objectives.
    I always look at 100% on my 22″ samsung t220 display at only 200usd and i have always the feeling that there is noise on nef (raw files) in lightroom which doesn’t appear so much in nx2 with all camera settings recognized by nx2.
    however, even with default of lr3.2 : 25,1,25,0 printing from lr on 10×15 and 13×18 mm with standard sharpening is very good. i will try soon a4 210x297mm but i have a canon mp980 less good than epson r2880 and 5 cartdridges of 9ml is very expensive so a4 is not often.

    i process most of my images with capture nx2 and have fun with usm and highpass filter with u-points. however nx2 environment is slow, prehistoric, external slideshow with viewnx2…
    i try to switch from nx2 to lr3.2 but to be sure i keep my u-points (because find local brush with its masking not very powerful) i have purchased complete collection of nik plugins.

    I have lot of books of evening and scott kelby with examples and am very disapointed i can’t do same job in lr3.2 than with usm, lab mode and highpass filter with sometimes fusion masks. But reading posts like yours and others i discover than lr3.2 sharpening is not just a capture sharpening and I need to better understand sliders.

    all this discussion to say i am still learning detail panel but find a pity we can’t use as local adjustment.

    The big question never described on internet is local brush “clarity and sharpening sliders”. what are these ? how can we adjust sharpening with only one slider ? i suppose it is a gain slider so where are hidden radius and threshold ?

    kloskowsky, kelby,… all make capture sharpening with lr3.2 and switch to photoshop for creative sharpening. huumm strange…

    i miss a lr3.2 highpass filter …

    many thanks for advises
    best regards

    marc

  8. Update: with Lightroom 3 and the new 2010 Process Version, the effects of the Detail panel sharpening adjustments are much more pronounced. With this in mind, my new defaults are:

    Amount 35
    Radius 1.0
    Detail 15
    Masking 15

    Also, Clarity (on the Basic panel) is stronger in the 2010 Process Version so I’ve lowered that default to 10.

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