Explain USM to me please =)

[Kadath]

Obviously I can 'see' the differences when I hit the sliders. What I need to know tho is where I should draw the line, what level is MINIMUM, and what I'll see when I've gone too far.

Sam

[robertwgross]

Sam, what program are you using for editing?

---Bob Gross---

[defordphoto]

Got about three years? There is no way to just "explain" USM in one post.

http://www.google.com/search?hl=en&q=photoshop+unsharp+mask

There are so, so, so many variables that it is impossible to state a finite number, however with my 1DMKII and 20D I start out at 50/.01/0 and keep clicking at a 100% sample until I like what I see.

80% of USM is pure experience. Sharpening for web is different than print. I approach my prints with a different starting point. After some experience, you'll develop your own methods.

[Pekka]

Jay Arraich says it well in http://www.arraich.com/ps_tips_shrpn5.htm

One last thing that I’d like to say, and this is my opinion only, is that you should consider the possibility of not sharpening at all. I don’t think I’ve ever seen a Photoshop site that didn’t recommend automatically sharpening all images. I find that I can spot ‘Photoshopped’ images by their often bizarre level of sharpness. They look like they are scenes from an alien planet.
We live in a world that has smog, smoke, fog, humidity, motion, wind, vibrations, and which is alive. Absolute sharpness is not a natural condition. Excessive sharpness can often look fake, phony, sterile, artificial, and dead.

This is also the answer to "when I've gone too far?": when it is unnatural, phony, fake, excessive. Use your eyes. You will usually need SOME sharpening to overcome AA filter, but after that it is pure taste.

[Jesper]

How do you know when you've gone too far:

Watch for white halos around edges. If you start to see white halos, you're oversharpening. It's best to zoom in to 100% before doing sharpening, so that you can accurately see what's happening to the image. Note that when you have the USM dialog box open, you can still use the scroll bars at the sides of the image to scroll around the image (in PS CS at least).

How much is too much depends on your personal preference...

[Scottes]

It's also a good idea to flip between undo/redo to see the before & after. After a while of staring at the sharpened image you get used to it, so flip back to the unsharpened and back to the sharpened version.

[Kadath]

Thanks for the replies. I'm using photoshop CS for those who asked.

I got my first batch of photos back from Costco and I'm absolutely floored, I was concerned that my noobishness with CS and my color blindness (both kinds red/green and blue/brown) would have hampered me, but I like the results and those I've shown them to have at least feigned enthusiasm =)

Later this week I'll post a before and after in the critiques section and see whether folks around here agree with the choices I made or can help me see some better options.

Sam

[Kadath]

It's also a good idea to flip between undo/redo to see the before & after.

I did that a lot, but without a real frame of reference on what is 'correct' it was hard to draw the line and say 'OK, That's good enough for me'

Sam

[Scottes]

I did that a lot, but without a real frame of reference on what is 'correct' it was hard to draw the line and say 'OK, That's good enough for me'

Post an unsharpened photo. I'll sharpen it to my eyes, and go overboard a little and post both. It will be to my tastes, others will vary, but maybe someone else will post their version, too. It's also not a bad way to get some various settings to use as a starting point for others.