Epson 4870/4990 and sharpening

[engl]

Epson are in a better position to write a sharpening algorithm for their own scanners, since they know what the point spread function will look like for their specific lens/CCD combination, and thus can use deconvolution assisted sharpening. Photoshop is clueless about this and can only do basic sharpening (although their "smart sharpen" to some degree works like deconvolution, but with an estimated PSF).

So do Epson do this? I do not know, but Epson are not ignorant about deconvolution.
http://www.comm.utoronto.ca/~kostas/...roceed/138.pdf
(the above article is about another use of deconvolution, motion blur reduction)

It is of course possible that they do deconvolution but not linked to sharpening, or that they do none at all. I'm just saying that I'd test it and compare it with the other options. I should do exactly that myself, it is time to look over my sharpening workflow...

[Ken Lee]

Different images call for different types of sharpening. That's why the PhotoKit tool offers a variety of methods.

The way you sharpen a brick wall, may not be appropriate for skies or skin texture.

I prefer to sharpen the final image alone.

It's best to use a format large enough that sharpening is minimized.

[Kirk Gittings]

There are a couple of different issues being discussed here. All sharpening in PS (I presume the initial posters here are talking about a final sharpening when all the work is done) or Capture sharpening in the scanner software with final in PS or Capture in PS (at the beginning) and final in PS.

With Epson scanners I used to use the low setting for capture until I got PKS which I now prefer for capture sharpening. With other scanners, Imacons or drum scanners I prefer the capture to be done in the scanner software. I don't particularly like PKS's final out put sharpening, preferring usually a layered High Pass Sharpen that I adjust via the opacity slider for final output sharpening. I find PKS's final output sharpening to be too aggressive, though that could be adjusted too with the opacity slider.

Like Ken, i am a minimalist with sharpening. I don't like my images to have that crispy edge feel, but something more akin to a sharp enlarged print.

[gnuyork]

I would always opt for sharpening in photoshop rather than the scanning software. Scanner software sharpening is always a pretty blunt instrument compared to whats available in photoshop,

...and you can't undo it once scanned. It's always good to have options. That's what I like about PK. It makes the sharpening in layer adjustments that you can turn on or off, and even adjust.

[Keith S. Walklet]

When I first started using the 4870, I advocated using the MEDIUM sharpening setting in Epsonscan. At the time, it seemed to produce files that looked more like what I'd expect to see of a raw, unsharpened drum scan.

But, after I'd experimented with that for some time, I noticed that there were artifacts from the sharpening in the shadows that were permanent.

So, I no longer sharpen at capture with that scanner, nor my V-750, nor my NIKON 8000. All the sharpening is done in PS, with three typical approaches. 1. Sharpen only edges 2. Smart sharpen 3. Selective sharpening on a duplicate layer that can be modified via a mask, blurring, etc.

Too bad the scanner's own sharpening is not a layer that can be adjusted after the fact.

[Brian Ellis]

The instructions for PK Sharpen say to not use any other sharpening with it so I don't use any sharpening in the scanner or in Camera Raw or in the camera or anywhere else. Even before I started using PK Sharpen I didn't use any in the scanner because I rarely apply the same amount of sharpening globally to the entire photograph. IMHO global sharpening is an easy route to an over-sharpened photograph because as others have noted, some areas shouldn't be sharpened at all (e.g. the sky) and different areas of the photograph often call for different amounts of sharpening. I hate the over-sharpened look of some photographs so I always err on the side of under rather than over sharpening.

Kirk - not only can you reduce the opacity of PK Sharpen's final output sharpening, you also can apply it selectively with a mask, which is what I do. If I skip any of the three stages of PK Sharpen it's usually the second or "creative" stage.