Re: Photoshop USM and CMYK conversion

[martinjg@xxxxxxxxxxxxxx]

Title: Re: Photoshop USM and CMYK conversion

It all depends on your final output really.  If you are going to print which it sounds like you are since you are going to CMYK then it is good to sharpen a lot.  It is OK to create some noise in a sky in print.  In fact sometimes gradients like a sky print better with noise.  For printing I usually USM at 300-400% at .7 (notice the decimal) pixels at threshold 3.  Try it, it makes the little details pop without making the strange artifacting with a large radius.  3 seems way too high to me.  I never go higher than 1.3.

This does NOT work for QTVRs.  All the little noise artifacts will shimmer like snow when you pan around.  For VRs, a higher threshold and radius works better since a QTVR will never look that sharp anyways.


Martin





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From: Alan Zinn <azinn@xxxxxxxxxx>
To: panorama-l@xxxxxxxxxxxxxxxxx
Subject: Re: Photoshop USM and CMYK conversion
Date: Wed, Mar 1, 2000, 6:27 AM

At 06:20 PM 3/1/1999 +1100, you wrote:
>Hi,
>
>I need to convert some 40 in images (at 300 dpi) to CMYK.  I scanned myself
>with unsharp masking turned off because of excessive stitching and retouching.
>I wonder if there are any rules of thumb using USM in photoshop for images
>of given sizes.  I found an amount of 150 % with a radius of 3 pixels at a
>threshhold of 5 to 10 seemed to be fine.  I'd like to make sure if this is
>the best combination before I would regret. Lowering the threshhold would mess
>up the sky.  Or would it be better to sharpen different parts of the images
>separately?   Any help would be greatly appreciated.
>
>Zonghou Xiong
>

ZX
I don't know if this helps your problem but I have always understood that
one always archives a raw scan of each image.  Any changes are then kept as
a copy file(s) or best yet just save the Actions used for the USM's and the
tweaks used for each application the file needs - size, printer, paper, etc.
In any case the advise is never save the USM with the file.

AZ


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