Join Deke McClelland for an in-depth discussion in this video Gauging the ideal sharpening settings, part of Photoshop CS3 Sharpening Images.
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In this exercise we are going to gauge the ideal Amount and Radius values by which to go ahead and sharpen our image for output at 267 pixels per inch. I have opened two images; one that I created in the previous exercise. It is called actualprintsize.JPG. If you weren't with me in that exercise., you can go ahead and open that image from the 01HowItWorks folder. I also have opened the Stunning 12x8.JPG file. We saw in the previous exercise how the command Print Size under the View menu is a crock. This is the actual print size that we calculated by down sampling the image, using the Image Size command we downsampled the image to the screen resolution, which I am saying is 117 pixels per inch, that is what we are imagining for now.
So Now let's go ahead and gauge using this actualprintsize.JPG file, we can now gauge accurately what Amount and Radius values we want to use. So what I would like you to do, even though we havent talked about this command in detail yet, go up to the Filter menu, choose the Sharpen command and then choose Smart Sharpen and this got it right there and that brings up the Smart Sharpen dialog box. Now I am going to go ahead and zoom up the preview inside the dialog box to 200%, so that we can see it up close and personal and so that it weathers the storm to video here, so that you can see what I am doing.
I am going to take this Radius value down to 0.7 pixels let's say, and I think the Radius value looks really great. I think this Radius value looks nice and sharp and I will also take the Amount value from 250 down to a 150%. So this is the before version of the image and this is the after version of the image, a nice little bit of sharpening applied. Now it may seem like we are going a little bit overboard like we are over-sharpening the image.
Bear in mind that when you print an image, it goes through a little bit of a softening process, so you do have to bump up that sharpening Amount value. So you want a Radius value that looks good on screen, but then you want to take the Amount value up about 50% higher that you might normally want to do it. So if a 100% looks good, which it typically does, then you would want to go ahead and take it to 150 is it what I am saying. 0.7 looks pretty good to me. You can vary it anywhere from about 0.4 or 0.5 up to about 0.9, any value in that area would look pretty good, but I want you to write these values down.
So 150% and 0.7 and then click OK. Now you may recall our multiplier from the previous exercise we took 267 pixels per inch, which is the resolution at which we want to output the image, and we divided it by 117 pixels per inch, which is the resolution of our monitor, lets say our imagine monitor, which is 17 inch MacBook Pro screen and we came up with a multiplier of 2.28. We would now take that multiplier and multiply it, not times the Amount value, we will leave the Amount value alone, it will say 150%, but we will multiply the Radius value because we need the halos to thicken up in order to weather the reduction, in order to look good when we reduce the image in print.
So now lets switch over to this image right here, Stunning 12x8.JPG, which is the actual print version of the image, I will go ahead and zoom in to the 100% zoom ratio, so that we can see the image nice and big on screen. I will press the F key to switch to the full screen mode for a moment here and I will focus in on the eyes. Of course for those of you who are photographers already know this, but when you are sharpening portrait photographs, you want to keep an eye on those eyes. The eyes are the most important things because that's the portion of the image that has to remain in focus.
We might as well check out things like the nostril and the eyebrows as well and a little bit of the hair that will help us out. Now I am going to go up to the Filter menu, actually what I am going to do is I am going to press Ctrl+Alt+F or Command+Option+F on the Mac in order to repeat the last filter that I applied and I am going to do the math. The Amount value is set on 150%, that's great, we want to leave it alone. We are going to take that 0.7 Radius value, get out to your calculator once again, multiply it times the multiplier. So 0.7 times 2.28 in our case and of course that's based on the math that you have done for your own monitor.
If your screen has a different resolution, you would use a different multiplier, you may recall that from the previous exercise. So in my case though, assuming 2.28, we have 0.7 times 2.28 and it us gives us approximately 1.6 as a Radius value, 1.6 pixels and then we'll go ahead and click OK, in order to accept that value, and this is the sharpened version of the image. Now if I go ahead and zoom in just another click here to 200% so that you can see the things nicely in the video. This is the before version of the image, which looked just fine, which is really actually pretty much sharp enough, and then this is the after version of the image, which is over-sharpened, I would say. It's a little bit too tactile, a little bit too brittle but actually it's going to look really good when we print the image.
Just to give you a sense I will go ahead and zoom the image out, not to the 66.7% zoom ratio because that is going to give you bad transitions, but rather you want to take it out to the 50% zoom ratio in order to gauge that sharpness. This is the before version, this is the after version. Now on your video you are probably not seeing much of a difference whatsoever. However, if you are working along with me on your screen you are going to see a slight difference and its going to be just enough to make the image pop on the page and it's going to weather that storm, it's going to look absolutely great, it's not going to look overly soft, the way it would normally.
It's going to look nice and snappy, which is what you want. So what this is all about, this entire project has been about trying to preserve the sharpness that you see on screen when you go to print. Alright. That's it for this Chapter. In the next Chapter we are going to be talking about when you sharpen. Do you sharpen at the beginning of the process, do you sharpen in the middle some place, do you sharpen at the end? And the answer to all of those questions as it turns out is yes. Join me in the next Chapter and find out why.
- Understanding the effects of sharpening
- In-depth examinations of Unsharp Mask, Smart Sharpen, Emboss, and High Pass
- Smoothing an image with the Surface Blur, Despeckle, and Reduce Noise features
- Working with smart objects and smart filters
- Creating edge masks and non-edge masks
- Sharpening for digital-image capture using Camera Raw
- Gauging and exploiting luminance frequency
- Exploring creative applications of sharpening
- Sharpening a multilayer composition
- Sharpening eyes, hair, and out-of-focus backgrounds
- Reducing noise in a high-frequency image
- Determining ideal settings for commercial and inkjet output
- Sharpening very large-format images
- Sharpening an image for the web or screen output