Unsharp Mask

[1IRISHBOY]

I am getting good results with PS7 using unsharp mask  - but - I really don't understand exactly what Radius and Threshold do. I imagine if I understood these parameters better I could use them more effectivly. Can anyone help me out particularly with radius which seems to have radical effects on outcome?

If it matters I'm using a Canon 100-400L IS and 20D.

[francois]

I am getting good results with PS7 using unsharp mask  - but - I really don't understand exactly what Radius and Threshold do. I imagine if I understood these parameters better I could use them more effectivly. Can anyone help me out particularly with radius which seems to have radical effects on outcome?

If it matters I'm using a Canon 100-400L IS and 20D.
[{POST_SNAPBACK}][/a]

Did you read Michael's understanding USM (Unsharp Mask) article? If not then you can read it [a href=\"http://www.luminous-landscape.com/tutorials/understanding-series/understanding-usm.shtml]here[/url].
You can also read another essay about USM on CreativePro website here and if you need more then read this.

[1IRISHBOY]

Did you read Michael's understanding USM (Unsharp Mask) article? If not then you can read it here.
You can also read another essay about USM on CreativePro website here and if you need more then read this.
[a href=\"index.php?act=findpost&pid=58912\"][{POST_SNAPBACK}][/a]

THANKS Francois. Swiss precision as usual.  

[Jason Cory]

Ron Bigelow also has a great Sharpening Tutorial on his website. Do a google search and you'll find it. It goes much further than USM, too.