Re: Sharpening [was Re: Resolution and print quality]

[John Douglas <jackg@poboxes.com>]

Moring Bob,

Excellent post, that is also why we use selective focusing, subject or
portion of subject is in focus and fore and background are out of focus.

Best,

John

> From: "Bob Frost" <bobfrost@btopenworld.com>
> Reply-To: epson-inkjet@leben.com
> Date: Thu, 6 Jun 2002 13:47:22 +0100
> To: <epson-inkjet@leben.com>
> Subject: Sharpening [was Re: Resolution and print quality]
> 
> Kennedy (& Harvey),
> 
> I hesitate to continue this discussion, having been doing serious
> photography for only a couple of years, and being a scientist rather than an
> arts person. However, I don't agree that the only sharpening required is
> that necessary to replace that lost during scanning etc. This might be the
> case if your photography is of the 'record picture' type - trying to
> reproduce exactly the scene in front of the lens. But I don't think that is
> what most 'serious' photographers do. They 'enhance' their images, by every
> physical, chemical, and electronic trick in the book, to try to produce an
> unreal picture that satisfies their artistic interpretation of the scene.
> Enhancement of edges - sharpening - is surely just one of those tricks.
> 
> Painters have for a long time known that to enhance edges you lighten the
> paint on one side of an edge and darken it on the other. I was at an
> exhibition of paintings by Picasso, Matisse, etc only a few weeks ago -
> "Paris in the 20's" I think it was called - and I remember saying to my wife
> "Look at that marvellous example of the use of 'unsharp masking'. Looking at
> the paintings and prints of paintings in my house, I can see numerous
> examples of where the artist has emphasized an edge - to make it stand out
> from the background. And yes, if you peer at the paintings from 10" they
> look unreal, but stand back and you enjoy the effect the artist was trying
> to achieve.
> 
> A friend of mine who goes to art classes has been taught how to enhance
> edges by painting a darker line round the inside of the edge to make the
> object stand out - asymmetric sharpening (you can do this with usm on a
> layer by setting Blend mode to Darken).
> 
> With our new computer techniques, sharpening can be done by various means;
> usm is just one of them. But I maintain it is a valid artistic technique to
> make an object stand out, and that the amount of it that you need depends on
> the effect you want and on the viewing distance. An artist painting
> miniatures does so with delicate strokes and lines suitable for a close
> viewing; an artist painting murals uses larger brushes and strokes more
> appropriate for viewing at a distance.
> 
> The fault that many photographers perhaps have is of applying an equal
> amount of sharpening to the whole image. Painters don't seem to do that;
> they are more selective in what they sharpen and by how much. I have
> recently started being much more selective; one recent image that needed
> different amounts of sharpening in different areas was sharpened four times
> with 100% amount of usm. Then, using the History brush, I simply painted the
> appropriate amount of sharpening into the different areas of the image.
> 
> But all done for a viewing distance of 10 feet or more, which is what
> happens if I show my prints to a seated audience. Forget the fine detail if
> people are sitting 20 feet away; it's the overall composition and impact
> that counts. IMO.
> 
> Bob Frost (awaiting the flak)
> 
> ----- Original Message -----
> From: "Kennedy McEwen" <rkm@kennedym.demon.co.uk>
>>> 
>> IMO, sharpening is a process to compensate for losses in the image
>> capture and reproduction process, to return the image to a closer
>> approximation of 'reality'.  Consequently, images which are viewed at a
>> distance should, in principle, require LESS sharpening, because they
>> already approach the ideal with the finest details being just resolvable
>> and the limitations of the capture process invisible in any case.
>> 
>> One of the main reasons for making an image large to be viewed at a
>> distance is that it appears to have the same spatial spectrum content as
>> a real scene, governed only by the limitations of your eyes, otherwise
>> you might as well make it suitable for viewing at the normal 10" relaxed
>> close viewing distance.  Sharpening such an image makes it look false
>> and synthetic, and I would guess that this is exactly the sort of effect
>> that Harvey (and myself!) finds objectionable.
> 
> 
> -
> Turn off HTML mail features. Keep quoted material short. Use accurate
> subject lines. http://www.leben.com/lists for list instructions.

-
Turn off HTML mail features. Keep quoted material short. Use accurate
subject lines. http://www.leben.com/lists for list instructions.