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RE: filmscanners: Silverfast Unsharp Mask



The conventional wisdom is USM should not be done until the image is in its final size. If you do you color correction and sizing in Silverfast then doing USM is appropriate.

The USM feature in Silverfast is superior to the default method in Photoshop because it works in LAB space and only on the luminance channel, which will not make any changes in the color. In Photoshop you can sharpen in LAB space just takes a few more steps.

David

 

-----Original Message-----
From: RogerMillerPhoto@aol.com [mailto:RogerMillerPhoto@aol.com]
Sent: Sunday, October 28, 2001 2:02 PM
To: filmscanners@halftone.co.uk
Subject: Re: filmscanners: Silverfast Unsharp Mask

 

I think you would be doing the right thing by not using USM in SilverFast.  As I mentioned before, I think it was intended for users who would be doing no further processing with Photoshop or other graphics software and were going directly to press with the scanned image.  By using unsharp masking in SilverFast, and more USM in Photoshop, you are asking for trouble since "double sharpening" like that can get out of hand very quickly.  And the amount of sharpening needed depends on your final image size as well.  That might explain why the image in the SilverFast preview looks different than in Photoshop.  When sharpening an image, you should view the image on your monitor at "actual pixel" size.  As I recall, the double sharpening method advocated by Bruce Fraser uses some edge sharpening, so I doubt you could accomplish the same thing by starting with USM in SilverFast.  I suspect that the rea! son you never heard from anyone who is using USM in SilverFast, and then more of it in Photoshop, is because no one is doing it.  Any your attempts seem to indicate that it doesn't work.  Good luck.

In a message dated 10/28/2001 9:24:47 AM Pacific Standard Time, jdubikins@hotmail.com writes:



>From: RogerMillerPhoto@aol.com
>My alibi is that I stated, "As a general rule, sharpening shouldn't be done
>more than once...." and even Bruce Fraser indicates that my comments are in
>agreement with "conventional wisdom."  Nevertheless, you and Michael
>Shaffer are quite correct in pointing out that there are more sofisticated
>sharpening techniques that may give improved results compared to the
>"sharpen once just before printing" method that I usually use.  I've tried
>Bruce's method, and another extremely involved multi-sharpening method, and
>wasn't able to make them work well for me (probably my fault).  Also, I
>have a certain bias against the SilverFast sharpening since SilverFast
>seems to default to sharpening in some random fashion whether I want to use
>it or not.  I don't even recall if SilverFast allows for the adjustment of
>the sharpening level.  Thanks for your comments.m  I'm sure the person who
>posted the original question appreciates the discussion as well.
>

Yes, I did appreciate the discussion, and I picked up a few things, though
none of it really had to do with my original question, which was how might
people be using Silverfast's USM feature in combination with Photoshop's.  
In my own experimentation, SilverFast USM intensity of 80-120 and threshold
of 2.0-4.0 seems to find the edges pretty well, but it can end up being too
much sharpening to permit any further refinement in Photoshop.  Much less
sharpening than this in SilverFast, and it is difficult to see in the
preview.  I think that the SilverFast preview for USM simply doesn't work
very well.

My conclusion is to do as you originally suggested (whether for the same
reason or not) and just not use USM in SilverFast and do it all, whether
once or twice, in Photoshop.

Joel W.

 



 




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