In Photoshop, I've got a master PSD image file with all mask and adjustment layer treatments, but no sharpening at all. I save for web and create a JPG at 1200px. Now, I bring that file back into Photoshop for some sharpening.
What's a quick and effective way to sharpen? I've read that using Filter -> Sharpen twice is good, but to me the outcome looks a bit over-processed. Is Smart Sharpen a better tool than just Sharpen? What about Sharpen More, Unsharp Mask, and Sharpen Edges?
There are a number of different lines of thought on this issue, and it seems that each one vehemently defends itself as the "one true way" to sharpen your image. In my experience, it comes down to personal preference and the specific image that you're working. Keep in mind that "sharpness" is really just an area of high contrast along an edge or line in your image. There are three primary methods that people use, but each have the fundamental effect of increasing this contrast:
The other filters (Sharpen, Sharpen More, and Sharpen Edges) I find to be less useful, because you have much less control over how they are applied to your image. But in some circumstances they may be appropriate.
This website has a really nice comparison of the high pass filter to the unsharp mask, and Ron Bigelow has a really detailed series of articles on each of the different sharpening methods. But I think the best thing to do is open up a few different copies of an image, apply different sharpening methods to each, and see which ones you like best.
I'd like to chime in, albiet a bit late. Sharpening is not a one-size-fits-all thing. In an ideal world, you would sharpen each image individually for optimal results. This isn't an ideal world and most people who process volumes of images want some compromise setting that gives a good effect most of the time.
Rule of thumb 1: Never sharpen at other than the final intended size.
Rule of thumb 2: Do not save in a lossy format such as JPEG, reopen the file, and then sharpen. Simply create a merged layer on top of all the other layers and sharpen that, then save for Web.
Rule of thumb 3: Before sharpening, convert to the output color space, sRGB. This is a weaker rule than 1 or 2, but you're going to need to do this anyway, so its better to perform the operation with the destination gamut in play.
Rule of thumb 4: Save your unsharpened original so if you need to resize, repurpose, or revisit the sharpening, you have the source image with edits but no sharpening halos.
To better understand what's going on here, it's useful to understand how sharpening actually works. What happens in almost all sharpening algorithms is that edges that contrast in luminance more than some threshold amount are identified as "edges." These edges are made to look sharper by increasing the luminance of some number of pixels on the bright side of the edge and decreasing the luminance on the dark side.
Over the years, there has been much debate about color artifacts introduced by sharpening, hence the high-pass method or sharpening the L channel in the LAB color mode. At this point, the amount of research Adobe (in particular) has done makes them well qualified to cook up sharpening algorithms that will effectively sharpen without undesirable artifacts.
All Photoshop sharpening algorithms work just fine for Web output provided you have 1) a composite layer (as I described previously); and 2) you have resized the image to its desired output size. You may have better results with less intervention required on your part by using Sharpen or Smart Sharpen. It depends how much you trust the smarts of these filters -- trying them on a representative sample of images will tell you which you like best. For ultimate control, Unsharp Mask is still the tool to use. You pull all the strings with Unsharp Mask and don't rely on smart-anything to make decisions for you.
Finally, many professionals swear by NIK Sharpener Pro. You can download a demo from their site and take it out for a spin. If you like their results better, you can evaluate whether their results are better than Adobe's.
I personally use a combination of the High Pass filter and Overlay.
After this, you should be able to use lower values of Sharpen to achieve the desired result.
Hope this helps.
I use smart sharpen in Photoshop at 100% and 1.4 pixel radius for web images. This isn't ideal for all images, but it's a good start.
I wouldn't suggest running the sharpening routine multiple times. Instead, use the percent to increase/decrease the amount, and just run it once.
First, I wouldn't export out the image and the continue editing it. In my workflow, once I Save for Web... it's done.
Secondly, resize the image before exporting. Photoshop has a couple options for reduction to control the resampling type. The default tends to blur things a little bit, but it depends on the image.
For sharpening, I tend to use Unsharp Mask. I have my default settings pretty low, apply it once, then hit command/control+f a few times until it's too much, then undo a bit.
