luminance sharpen vs others

[cjphoto]

I have been getting good results w/ output sharpening (300 inkjet matte--with no prior sharpening). but found luminance sharpen in the photokit image enhancement set to be pretty interesting. It seems a bit 'grainy' at level 4, but level 2 and 3 works looks great at native size. ( 13.57x13.57 at 300dpi, which is the size tiff produced by the Kodak DCS Proback) I have not tried it up'rezed.

I am printing on Hahnemule Photo Rag with Studioprint RIP using Ultrachome.

Does anyone have any other experiences with sharpening / SP RIP / etc?

[Jeff Schewe]

The original sharpeners included in the original PhotoKit were; Edge Sharpener, Luminance Sharpener and the High-Pass. From that we designed the full PhotoKit Sharpener product. We discovered that edge sharpening is suitable for regaining the effective sharpening lost in the digitalizing process of capture or scaning. The Luminance sharpener is designed as a general purpose sharpening to only sharpen the luminance of an image without affecting the color channels. High Pass is basically designed more for final output sharpening.

I would suggest reding this article about sharpening: "Thoughts on a Sharpening Workflow" by Bruce Fraser (http://www.creativepro.com/story/feature/20357.html)

[cjphoto]

Bruce's article is a brilliant approach to sharpening, and at the very least clarifies the why's and hows. It illustrates, however, a problem that I discovered when using his suggested workflow. If you take a look at the sharpened figure 3 and 4 in his article, you'll see tiny artifacts that run parallel to the edges of the slats in the uppermost vane. They are not contiguous to the physical edge of the surface to which they relate, indeed they are running through midair. I experienced the same effect in a chain link fence in one of my images. Clearly, this must be considered undesirable, and is what led me to the luminance sharpening conclusion. I understand, after reading your reply above and Bruce's article, that is not the right approach either. That said, most of what I do is intuitive, and whatever works is ok by me.

At any rate, I now realize that I should invest some time in discovering the power of Bruce's sharpening workflow, and I'll certainly let you know how I fare. So how should I deal with the strange "flying artifacts" mentioned above?

FYI, I really appreciate your products, particularly the "toning" set and "B&W to color" set. The platinum tone is perfect for most of my photos, and works well on most images straight out of the box. On others, I find that a "filter" application from the "B&W to color" set will enhance the subsequent platinum tone.

thanks for your support,

Chris Jones

[Jeff Schewe]

It's REAL HARD to get web sized jpg's to accurately show anything other than web sized jpg artifacts. . .if you are seeing hard halos in your images for print, you are either over-sharpening of using the wrong approach. Also note that the ONLY way to judge sharpening for prints is to make the prints and evaluate them. You really can't tell diddly on a computer display about how the sharpening will look printed.

[cjphoto]

I am well aware of the hard halos that most of us suffered through in the early days of oversharpening. I tend to exist on the 'less is more' side of things, and that is why your effects are so good--they are all quite subtle. Since my last post I re-read much of the detailed user manual and played with the 3 step sharpening workflow. And yes, I can see that printing the results will be critical in determining the quality. I may well have been describing an effect that isn't visible on a printout. I will spend tomorrow printing, and will report back.

Again, thanks for all of your shared knowledge,

Chris Jones