You will need to be a little more specfic as to what you are trying to acheive.
Are you refering to LPI (lines per inch) Correctly? LPI should have little effect on the image it's self other then perhaps dot gain, max density, or to calulating optinum image resolution required. LPI is simply a measure of halftone dot size on an imagesetter or platemaker. It is not a measure of image resolution like PPI (Pixels Per Inch) or the miss used DPI (Dots per inch). Image resolution dose have an effect on matrix operation or filters such as sharpening and blurs.
Example: Sharpeing a 800x800px image would require half the setting required to achieve the same effect on a 400x400px image.
Note: DPI (dots per inch) is sometime interchanged with PPI, while this is correct in some circles the perfered method is PPI (PPI per inch) DPI is an old term used to define the cells or dots that make up the halftone dots of an imagesetter. Which is why you spec a job on the imagesetter as 150lpi at 2400dpi.
There are no standard setting for adjustments, everything depends on the image and it's intended output device. One could define a basic catch all setting that would work ok on most image, based on specfic file sizes, input device, and output device. I would extensive testing to see what works best for you and you workflow.
I have worked in catalog publishing, printing gravure and offset presses printing following SWOP standards.
For basic shapening I like to start with USM, at about 150-175, radius 1 pixel and a threshold of 0-3. I either sharpening just the L channel in while in LAB mode, or if the image comes as a CYMK, I sharpen it and then fade the effect using Edit>Fade, setting the blend mode to luminosity. The basicly the rule I uses is to sharpen till I think it is enough on screen and the bump the sharpeing up 10% -15% as screen will always look sharper on screen then it ever will on the print.
For more advanced or problematic images I use a method similar to following sometimes called the highpass sharpening method.
http://www.creativepro.com/story/feature/12189-2.html
As for Levels, adjustmets, and etc... I couldn't begin to tell you what you need to know, it depends completely on your output device and what you wish to acheive.
If you what to know more, I would check out the following book:
Professional Photoshop, By Dan Margulis; Its the best book ever written on prepress and color correction for print on the market. I made it requried reading to my staff. It's a book all Designers, Production artist, and Art directors should read it before ever preparing work for print.
J. Stuart J.
[This message has been edited by jstuartj (edited 06-07-2003).]
posted 06-07-2003 01:05
