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unsharp mask question

PostPosted: Fri Aug 17, 2007 1:09 pm
by jamesw
what do you guys typically use for your settings with USM?

PostPosted: Fri Aug 17, 2007 1:17 pm
by sirhc55
There is no fixed settings because it all depends on the photo itself. Some pics will require none, some will required a little and some even more. Check your pics as you apply and go with the one that is sharp but has not introduced ”halos”.

Re: unsharp mask question

PostPosted: Fri Aug 17, 2007 1:21 pm
by Laurie
jamesw wrote:what do you guys typically use for your settings with USM?

USM stands for UnSharpen Mask?????????

PostPosted: Fri Aug 17, 2007 1:30 pm
by jamesw
OK,

so anyone got any tips or explanation of how the tool works itself?

I use it, but fairly touch and go... i'd like to know how it actually works I guess

Re: unsharp mask question

PostPosted: Fri Aug 17, 2007 1:31 pm
by jamesw
Laurie wrote:
jamesw wrote:what do you guys typically use for your settings with USM?

USM stands for UnSharpen Mask?????????


yep thats what I've seen it refferred to commonly around the place?

Re: unsharp mask question

PostPosted: Fri Aug 17, 2007 1:40 pm
by Laurie
jamesw wrote:
Laurie wrote:
jamesw wrote:what do you guys typically use for your settings with USM?

USM stands for UnSharpen Mask?????????


yep thats what I've seen it refferred to commonly around the place?

OOOOOOOOOOOOOOOOOOOOOOOOOOHH!

Why would you want to unsharpen something????

PostPosted: Fri Aug 17, 2007 1:46 pm
by rah
jamesw wrote:OK,

so anyone got any tips or explanation of how the tool works itself?

I use it, but fairly touch and go... i'd like to know how it actually works I guess


This one is a basic explanation that helped me..


http://www.iforphotos.com/guides/post-processing-basics?page=0,5

or wikpedia for more detail

http://en.wikipedia.org/wiki/Unsharp_mask

"The "unsharp" of the name derives from the fact that the technique uses a blurred, or "unsharp", positive to create a "mask" of the original image. The unsharped mask is then combined with the negative, creating the illusion that the resulting image is sharper than the original."

Re: unsharp mask question

PostPosted: Fri Aug 17, 2007 2:07 pm
by gstark
Laurie wrote:
jamesw wrote:what do you guys typically use for your settings with USM?

USM stands for UnSharpen Mask?????????


In Canon lens terms, it also can mean Ultra Sonic Motor, which is the type of (internal, to the lens) motor used to drive the lens focus mechanism.

If your confsued, then great; join the clubbbbbb.

:)

PostPosted: Fri Aug 17, 2007 2:21 pm
by jamesw


PRECISELY what I wanted! Cheers!


gstark wrote:
Laurie wrote:
jamesw wrote:what do you guys typically use for your settings with USM?

USM stands for UnSharpen Mask?????????


In Canon lens terms, it also can mean Ultra Sonic Motor, which is the type of (internal, to the lens) motor used to drive the lens focus mechanism.

If your confsued, then great; join the clubbbbbb.

:)


the 'wonderful' world of acronyms, huh.

PostPosted: Fri Aug 17, 2007 2:22 pm
by ATJ
There is a technique that is often used for nature photographs when publishing for the web: http://www.naturescapes.net/phpBB2/view ... p?t=105932

This doesn't always work, but often produces good results. You don't have to worry about the settings for USM and you just Sharpen as many times as needed to get the result you want.

PostPosted: Fri Aug 17, 2007 2:50 pm
by Greg B
Don't you just love terminology which seems completely arse-about?

Personally, I use slightly more amount than that suggested in the linked article (maybe 80% as a starting point) and slightly less than 1 pixel.

But it is all about getting to know the effect settings have.

I believe it is generally preferable to use the USM after resizing the image (if you are resizing)

The benefits of applying USM to (copies of) the same image file 4 or 5 times and comparing the resulting
images can be enormous....
say
Amount 40% - 60% - 80% - 80% - 80%
Pixels 0.8 - 0.8 - 0.8 - 1.0 - 1.2

(and so on as much as you like)

You will soon get an idea of what does what

PostPosted: Fri Aug 17, 2007 3:12 pm
by stubbsy
At the risk of stating the obvious - Smart Sharpen in the newer flavours of Photoshop is better to use than Unsharp Mask. But see my disclaimer below :wink:

PostPosted: Fri Aug 17, 2007 6:53 pm
by gooseberry
I tend to use a couple of rounds of sharpening, depending upon the image.

To overcome the bluriness of the AA filter, I tend to use a fairly high Amount, with a very low Radius (0.3 to 0.4) - this is also good for very fine detail.

For local contrast enhancement, another technqiue (named loamhirad) - Lo Amount, High Radius as mentioned by Photoshop expert Dan Margulis is quite popular.

Finally, after all image adjustments, if I have done some resizing, I may do a small amount of sharpening to overcome the bluriness of the resizing.

Sharpening in the L channel is recommended.

Oh, and as Peter mentions, Smart Sharpen seems to produce slightly better results.

PostPosted: Sat Aug 18, 2007 9:24 pm
by Matt. K
It is called 'Unsharp mask' because it masks unsharpness. Cute but true.