er,digital photography threads don't usually end up in computer related!! maybe it should,but its a first

can someone tell me what threshold,amount and pixels to use,for posting pics on the web and also for just tweaking my own pics? whats do they all mean? cheers

Troublemaker ;)

This depends a great deal on how the pictures come out of your camera in the first place. Some cameras use quite a lot of in-camera sharpening, others (like my Canon 300d) use very little and the pictures come out looking quite soft.

It also depends on how large the file size is, because the fewer pixels that make up the picture, the more obvious the effect is. That is why you should always use USM last, after you have done any re-sizing (for the web etc) and other adjustments.

If your pictures look slightly soft to you, then try some initial settings like 200%, radius 0.6 and threshold 3. It will soon be very obvious if you have over done it. Then it's just a case of tweaking until you are happy.

I use a plug-in in Photoshop called CSpro, which is available from http://www.fredmiranda.com/software/ I find this does a very good job of automatically setting USM and you can vary the amount you want to use. I think it costs about $15 to download. There is a version called Intellisharpen Pro for general use, whilst others are available for specific cameras.

er,digital photography threads don't usually end up in computer related!! maybe it should,but its a first

can someone tell me what threshold,amount and pixels to use,for posting pics on the web and also for just tweaking my own pics? whats do they all mean? cheers

Press the F1 key. This will bring up an item called 'Help'.

UB:D

This link may be helpful http://www.microsoft.com/windowsxp/digitalphotography/learnmore/fixit/sharpening.asp

Edited to add this interesting link, if you can put up with the slightly patronising voice ;)
http://www.russellbrown.com/tips/moviesps/AdvancedSharpening.mov

Here's what I do with a Nikon D2H.

Convert to Lab Color
Select lightness channel
Unsharp mask 90%, 1.6, 5
Convert to sRGB

The idea being you only want to sharpen the edges of the images (hence the ligtness channel selection).

As to find out what they do - put USM in preview mode and slide them up and down :D

tiggers.

Also consider doing some local contrast enhancement (LCE) before going mad on the sharpening side, usually gives a more natural look.

LCE also uses the USM widget but with settings around:
Amount: 20%
Radius: 50 pixels
Threshold: 0

Alter the Amount to taste before sharpening.

Also, when using USM to sharpen, only do it once. I.e. if the first go doesn't do exactly what you want, undo, then adjust settings before applying again. Constant small goes with USM to get where you want will quickly kill the image.

Cheers

Ian

great stuff,cheers,taught me a lot that lot (as well as a moderator:))