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[OM] Sharpeining, was: Flickr account problems

Subject: [OM] Sharpeining, was: Flickr account problems
From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
Date: Fri, 12 Dec 2008 10:31:15 -0500
After reading Bruce Fraser's book "Image sharpening with Adobe PhotoShop 
CS2" I netted it all down to:

When sharpening with unsharp mask for prints (not for the screen):

First, crop and resize the image to final print dimensions and pixel 
density (eg; 8x10 at 300 ppi)

Second, adjust the on-screen magnification to 25-30%.  Then sharpen 
until the on-screen image looks slightly crunchy or slightly oversharpened.

The rationale for the magnification is this:  The on-screen viewing size 
of 25-30% is to adjust for the difference in resolution between screen 
and print.  For example, the height of my viewable screen area is 9.5 
inches.  The vertical resolution of the screen is 864 pixels or 91 
pixels per inch.  But the print resolution I normally use is 300 ppi. 
To get the viewing magnification for sharpening divide the screen 
resolution in ppi by the print resoluti0n in ppi.  In my case it's 
91/300 or roughly 30%.  I sometimes use 240 ppi for prints and in that 
case I should use a screen magnification of 38%.  But precision is 
probably not justified here so 35 or 40% is probably fine.

The rationale for slightly oversharpening is that the printing process 
will have a slight softening effect.  When it looks just a tad too 
crunchy on the screen it will probably look about right on paper.

I hope that answered the question you haven't yet asked. :-)

Chuck Norcutt


Fernando Gonzalez Gentile wrote:
> I might agree with Chuck - so far, have specific reasons.
> 
> Password can be recovered, I could do so a couple of times but was sort 
> of trial and error and being patient, a waste of time.
> 
> It has some specific advantages though, which you might judge useful or not.
> 
> Personally, I avoid Tags and Contacts and joining Groups.
> 
> Currently I'm not caring too much about uploading to a website: have a 
> couple of questions on unsharp mask for Chuck and Moose and everyone 
> else, which I'm still thinking how to properly ask - better study a 
> little more before.
> It all started when Chuck posted a link to high-pass sharpening ( on 
> Nov. 20 ), and I am about to re-scan everything from the beginning ... :-\
> 
> Fernando.
> 
> Chuck Norcutt wrote:
>> My advice is just avoid Flickr  :-)
>>
>> I dislike that site so much that I typically won't even bother to look 
>> when someone posts a link from there.
>>
>> Chuck Norcutt
>>
>> Darin wrote:
>>   
>>> Hello list,
>>>
>>> I seem to have forgotten the password to my Flickr account, and I'm
>>> having no luck with their password recovery system. When it asks for
>>> my alternate email address, or other info, such as birthdate, country
>>> of residence and postal code, it keeps telling the info I provided
>>> doesn't match the info in my profile.
>>>
>>> Has anyone else ever had a problem like this, or know of a way around
>>> it? Their help center is, IMO, absolutely worthless, it just keeps
>>> telling me to do the same thing I've been doing over and over. Until,
>>> eventually it locks me out for 24 hours, which it's done twice so
>>> far.
>>>
>>> Any help would be greatly appreciated!
>>>
>>> Darin
>>>     
> 
> 
> 
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