New Feature: Playlist Center! Pick a topic and let our playlists guide the way.

Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member

Understanding amount and radius

From: Photoshop CS3 Sharpening Images

Video: Understanding amount and radius

In this exercise we are going to see how you can adjust the degree of Sharpening that's applied to the image using a couple of different numerical values. Now there are a variety of different filters that are available to you where sharpening is concerned, there is Unsharp Mask, Smart Sharpen, High Pass, Emboss, even Gaussian Blur as it turns out. Now every one of these filters works differently, but most of them sharing in common ad Amount value and all of them sharing common something analogous to a Radius value. So we're going to see how those amount and Radius values work.

Understanding amount and radius

In this exercise we are going to see how you can adjust the degree of Sharpening that's applied to the image using a couple of different numerical values. Now there are a variety of different filters that are available to you where sharpening is concerned, there is Unsharp Mask, Smart Sharpen, High Pass, Emboss, even Gaussian Blur as it turns out. Now every one of these filters works differently, but most of them sharing in common ad Amount value and all of them sharing common something analogous to a Radius value. So we're going to see how those amount and Radius values work.

Well take a look at the specific filters and the application of those filters in a later Chapter. For now notice that I am still working inside of the Sharp Shapes.PSD image, found inside the 01howitworks folder. I've got my Standard Layer Comp active, I am going to go ahead hide the Layer Comps palette and I am going to bring out my Layers palette. I am going to expand my palette so I can see the Layers palette down here. If you are looking at your Layers palette too, you should see a series of four Smart Objects comp #1, comp #2, comp #3 and comp #4, as well as this group called the ingredients.

We are most interested in these comps here, these Smart Objects to which I have applied editable Smart Filters. Now if you're not sure whats going on with Smart Objects and Smart Filters or you have limited experience with them, don't worry. I am going to show you how they work in detail in the later Chapter, but for now I want you to notice that comp #1 is the sharpened version of the standard image, whereas, I'll turn it off and turn on comp #2, which is the sharpened version of the gradient image with texture, notice that. Then comp #3 is a smooth version and sharpened as well of the standard image, and then finally, we've got comp #4, which is a smooth and sharpened version of the gradient image.

The ones that we are going to work on, we are going to be playing around with comps #1 and #2 here. So go ahead and turn comp #1 on, and I am going to switch to the full screen mode so that I have a little more room to work. I am going to twirl open the comp #1 item here by clicking this down pointing arrowhead over here in the right-hand side of the Layers palette and that reveals my Smart Sharpen filter. So I have sharpened this image using Smart Sharpen,. To adjust its settings go ahead and double-click on Smart Sharpen and you'll see right away the Amount and Radius values.

So several other options going on inside this dialog box. For now all we are concerned about is Amount and Radius, and here's how they work. Amount controls the amount of sharpening you apply. It's pretty easy to understand, pretty easy to get a sense of whats going on. All you do, if you need more sharpening, you increase the Amount value and that gives you more of a tactile, more of a crunchy fact. And if that's too tactile or crunchy, as it obviously is here, then lets go ahead and take the Amount value down in order to create a more subtle effect.

For Now I am going to leave the Amount value set to 250% so we can focus on the slightly more difficult to understand option, which is Radius. It also happens to be the more important option where sharpening is concerned. Radius defines the size of the halos. Lets go ahead and zoom in on this preview, this in dialog box preview right here, move it down a little bit. You can see of course that we have a dark halo tracing the dark side of the circle and a light halo tracing the light side of the circle. The size of that halo is defined by the Radius value.

So right now we have one pixel on the outside and one pixel on the inside. Now it's called Radius because Photoshop actually goes through and scrubs around every single pixel, so it's scrubbing in these tiny little circles all over the place and the size of those circles is defined by the Radius value. But where we are concerned, it ultimately defines the size of the halos. So I am going to increase this Radius value, lets say to 12 pixels and you'll see that our halos grow in size to 12 pixels, they're all soft halos. So notice that the halos are dissipating, or dispersing really, over the course of these 12 pixels.

Now Photoshop tends to use a Gaussian distribution curve for this softness, and that means that the halos are actually a little bigger than the Radius value. So these halos are more like 14 pixels in size. But it doesn't really matter that much exactly how big they are. We are more interested in the visual effect. Now in this case I'll go ahead and move my dialog box so we can see this for a moment. Its not really a sharpening effect at this point; we are getting more of a high-contrast edge effect, so we are definitely sharpening the heck out of this texture in the background.

But where the big objects are concerned, they don't tend to look so much sharp, just rounded, almost contoured, shaded if you will. So basically how things work is this way, if you want a true sharpening effect and you want to combine a high Amount value with a low Radius value and you can go as low as 0.3 pixels. You can go even lower than that; it's just that the effect really drops off in the 0.1 and 0.2 range. You really don't see anything until you have this guy cranked up to about 0.3.

But it does make a difference. Notice there. I'll go ahead and zoom in even farther so we can see this at work. I'll go ahead and click and hold on the in dialog box preview. This is what the effect looks like before, unsharpened, and this is what the image looks like after this Amount value of 250% and the Radius value of 0.3 pixels is applied. So we do have a slightly sharp effect applied at this point. You can also combine a very low Amount value. Lets go to just like 25% with a very high Radius value, lets say 12 pixels, and that's going to give you more of a heightened contrast effect.

Allbeit, the contrast is going to be applied to the edges but it's not going to look so much sharp as contrast-y. So I'll go ahead and click OK in order to accept those values, once again they are 25% and 12 pixels, I'll click OK, and just to give you a sense of what kind of difference this makes, lets go ahead and zoom in just little bit here and I'll turn off this Smart Sharpen filter by clicking on its eyeball. This is the unsharpened version of the image; this is the sharpened version of the image. So slight modification there. Now lets take a look at combining Amount and Radius with the gradient version of the image.

I am going to turn off the comp #1 Smart Object and turn on the comp #2 Smart Object so that we can see the gradient version of here. I'll go ahead and open it up as well, expand it so that we can see the Smart Sharpen item. Lets go ahead and zoom out just a little bit so that we can take in more of the image at a time, and I'll double-click on the Smart Sharpen. Lets not worry so much about the Amount value. You notice that it's cranked through the roof right Now it's 500%. Lets just go ahead and raise that Radius value once again to 12 pixels and click OK order to accept that. And now you can see if we scroll to the top we have a very, very dark black, thick halo at the top on the inside edge of the serpentine line.

Up there toward the top of the image, we have a white halo on the outside of course, and notice that they are growing slimmer and slimmer as we work our way down to where we are almost losing the Radius entirely at this point. Of course, right there we have very little in a way of any halo occurring at all because we have very little in a way of a difference between the line and its background, and of course the light halo is also dissipating over time and then they switch places and they flair out once again toward the bottom area of the image.

So that's how it's working. And you might think of the Radius as being a blur because that's what it really is, it's a blurred halo that's been drawn around the image and that's the way Sharpening works inside a Photoshop. Photoshop uses blur, specifically Gaussian Blur in most cases, in order to create the effect of sharpening, as strange as that sounds. So now that's the overview of how Sharpening works inside of Photoshop. In the next exercises we're going to see how you can gauge the sharpness of an image on screen.

I'll start things off by showing you how you can measure your monitor's resolution.

Show transcript

This video is part of

Image for Photoshop CS3 Sharpening Images
Photoshop CS3 Sharpening Images

115 video lessons · 16967 viewers

Deke McClelland
Author

 
Expand all | Collapse all
  1. 50m 30s
    1. Why every image needs sharpening
      2m 38s
    2. Understanding the effects of sharpening
      5m 26s
    3. Understanding the mechanics of sharpening
      4m 19s
    4. Understanding sharpening and gradual transitions
      3m 21s
    5. Understanding sharpening and noise reduction
      4m 0s
    6. Understanding amount and radius
      7m 50s
    7. Measuring your screen resolution
      6m 19s
    8. Using reliable zoom ratios
      5m 30s
    9. Calculating the actual print size
      4m 54s
    10. Gauging the ideal sharpening settings
      6m 13s
  2. 59m 31s
    1. Everyone knows you sharpen last (and everyone is wrong)
      1m 8s
    2. Understanding the conventional sharpening workflow
      5m 4s
    3. Flattening and saving to TIFF
      6m 39s
    4. Downsampling (and why you shouldn't upsample)
      6m 8s
    5. Understanding last-step sharpening
      6m 44s
    6. Recognizing problems with the conventional workflow
      9m 38s
    7. Erasing sharpening with the history brush
      4m 30s
    8. Using alternative sharpening workflows
      2m 37s
    9. Sharpening a scanned photograph shot on film
      2m 45s
    10. Sharpening a digital photograph
      3m 6s
    11. Sharpening specific details
      3m 43s
    12. Finding broad workflow conclusions
      2m 49s
    13. Learning that technique trumps timing
      4m 40s
  3. 1h 27m
    1. Comparing and contrasting neighboring pixels
      1m 6s
    2. Using the Gaussian Blur filter
      4m 25s
    3. Using Gaussian luminance distribution
      4m 47s
    4. Using the Unsharp Mask filter
      4m 54s
    5. Understanding the history of Unsharp Mask
      3m 51s
    6. Building your own USM with Gaussian Blur
      7m 35s
    7. Using the Smart Sharpen filter
      7m 35s
    8. Compensating for camera shake
      8m 50s
    9. Building your own Smart Sharpen with Lens Blur
      6m 59s
    10. Using directional sharpening with Emboss
      9m 13s
    11. Using Smart Sharpen extras
      8m 56s
    12. Using Convolution Kernels for more accuracy
      7m 8s
    13. Using the High Pass filter
      7m 32s
    14. Using Luminance Sharpening
      5m 5s
  4. 2h 14m
    1. Smoothing filters, smart objects, and masks
      1m 25s
    2. Using the Median filter and Dust and Scratches
      7m 7s
    3. Using Smart Blur and Surface Blur
      6m 12s
    4. Using the Despeckle filter
      8m 17s
    5. Softening flesh tones selectively
      10m 15s
    6. Using the Reduce Noise filter
      7m 27s
    7. Combining smoothing and sharpening
      8m 24s
    8. Making an image into a smart object
      9m 24s
    9. Applying editable smart filters
      6m 8s
    10. Combining two smart filters
      8m 5s
    11. Assigning a filter mask
      5m 59s
    12. Nesting one smart object inside another
      10m 32s
    13. Employing a static High Pass layer
      8m 59s
    14. Matching static pixel-level edits
      4m 37s
    15. Avoiding clipping with luminance blending
      9m 7s
    16. Sharpening and smoothing
      6m 36s
    17. Making an edge mask
      8m 14s
    18. Making a non-edge mask
      7m 17s
  5. 1h 33m
    1. Sharpening with Adobe Camera Raw
      1m 29s
    2. Introducing Camera Raw (4.1 or later)
      8m 13s
    3. Understanding why to sharpen for source
      5m 14s
    4. Using Camera Raw’s sharpening control
      5m 52s
    5. Previewing limitations and tricks
      6m 45s
    6. Why downsampling doesn’t work
      3m 12s
    7. Reducing chromatic aberration
      7m 30s
    8. Using the Defringe option
      3m 32s
    9. Understanding high frequency, low radius
      5m 21s
    10. Raising the Detail value
      3m 6s
    11. Using on-the-fly edge masking
      5m 41s
    12. Sharpening a low-frequency portrait
      6m 36s
    13. Eliminating color noise
      4m 47s
    14. Reducing luminance noise
      4m 42s
    15. Correcting “false sharpening”
      7m 15s
    16. Reducing shadow noise
      5m 22s
    17. Approximating ACR sharpening in Photoshop
      8m 35s
  6. 59m 8s
    1. Gauging and exploiting luminance frequency
      1m 27s
    2. Using low-frequency source sharpening
      5m 53s
    3. Using High Pass for portraits
      4m 19s
    4. Actioning a low-frequency edge mask
      7m 42s
    5. Modifying the source sharpening
      5m 21s
    6. Using high-frequency source sharpening
      5m 26s
    7. Using Smart Sharpen for cityscapes
      3m 2s
    8. Actioning a high-frequency edge mask
      5m 4s
    9. Downplaying color artifacts and clipping
      4m 4s
    10. Sharpening a medium-frequency image
      5m 24s
    11. Sharpening a layered composition
      7m 16s
    12. Sharpening for multiple frequencies
      4m 10s
  7. 1h 8m
    1. Who needs dull when you have sharp?
      56s
    2. Focusing in on a person’s eyes
      4m 22s
    3. Blurring the area outside the eyes
      4m 22s
    4. Sharpening eyes and other details
      5m 38s
    5. Darkening the lashes and eyebrows
      7m 13s
    6. Sharpening dark-haired people
      5m 2s
    7. Edge mask and emphasize
      3m 39s
    8. Nesting a Smart Sharpen effect
      4m 48s
    9. Density mask sharpening
      5m 35s
    10. Adding depth of field
      4m 39s
    11. Sharpening a background
      4m 23s
    12. Masking background from foreground
      8m 51s
    13. Eliminating halos around a person
      5m 38s
    14. Deepening and warming a background
      3m 28s
  8. 1h 18m
    1. Reverting back to convention
      1m 37s
    2. Understanding the use-neutral composition
      4m 15s
    3. Restoring much-needed antialiasing
      4m 2s
    4. Reducing noise in a high-frequency image
      7m 24s
    5. Making a third-level smart object
      3m 55s
    6. Preparing an image for print
      5m 18s
    7. Using ideal settings for commercial reproduction
      5m 37s
    8. Calculating very large-format settings
      5m 11s
    9. Using ideal settings for inkjet output
      4m 26s
    10. Sharpening for commercial reproduction
      5m 45s
    11. Sharpening for inkjet output
      4m 58s
    12. Revealing high-frequency multipass sharpening
      5m 21s
    13. Using Gaussian Blur to sharpen hair
      5m 41s
    14. Flatten, Save As, Resample, and Sharpen
      5m 9s
    15. Revealing low-frequency multipass sharpening
      3m 30s
    16. Sharpening an image for web or screen
      6m 22s
  9. 1m 50s
    1. Goodbye
      1m 50s

Start learning today

Get unlimited access to all courses for just $25/month.

Become a member
Sometimes @lynda teaches me how to use a program and sometimes Lynda.com changes my life forever. @JosefShutter
@lynda lynda.com is an absolute life saver when it comes to learning todays software. Definitely recommend it! #higherlearning @Michael_Caraway
@lynda The best thing online! Your database of courses is great! To the mark and very helpful. Thanks! @ru22more
Got to create something yesterday I never thought I could do. #thanks @lynda @Ngventurella
I really do love @lynda as a learning platform. Never stop learning and developing, it’s probably our greatest gift as a species! @soundslikedavid
@lynda just subscribed to lynda.com all I can say its brilliant join now trust me @ButchSamurai
@lynda is an awesome resource. The membership is priceless if you take advantage of it. @diabetic_techie
One of the best decision I made this year. Buy a 1yr subscription to @lynda @cybercaptive
guys lynda.com (@lynda) is the best. So far I’ve learned Java, principles of OO programming, and now learning about MS project @lucasmitchell
Signed back up to @lynda dot com. I’ve missed it!! Proper geeking out right now! #timetolearn #geek @JayGodbold

Are you sure you want to delete this note?

No

Thanks for signing up.

We’ll send you a confirmation email shortly.


Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

Keep up with news, tips, and latest courses with emails from lynda.com.

Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

   
submit Lightbox submit clicked
Terms and conditions of use

We've updated our terms and conditions (now called terms of service).Go
Review and accept our updated terms of service.