Thank you Carolyn
I'll put this to practice
Regards
Sent: Wednesday, July 13, 2011 6:56 PM
Subject: [photoshop-beginners] 1 way to use UNSHARP MASK
Ok, all....
Here are the steps I used to sharpen the photo for Benesesso....
#1...do all your other work first....sharpening is the last step you do with a photo prior to output or conversion from RGB to CMYK.
You can sharpen newspaper images or any other. Some can't be totally fixed but at least they can be improved upon.
NEWSPAPER NOTES:
When looking at a newspaper photo, you can see dots which make up the dark and light areas. These dots spread and soften...this is called Dot Gain.
To compensate for this ahead of printing in a newspaper, you can sharpen the image before it's output. There are several ways, but the USM (Un-Sharp Mask) is very effective. It offers control in 3 ways: the total amount of sharpening, the width (radius) of sharpening and the sensitivity (threshold) of what areas will or will not be sharpened. Using this tool improperly, however, can degrade the image. So a little practice will hone your skills.
The settings you will encounter are dependent upon many factors. Size, resolution, content of image, scanned or digitally shot....
A good practice setting for newsprint is 150 for the amount of sharpening. 1.5 for the radius and 2 for the threshold. A 1-column image can be lessened to maybe 85. A digitally-shot image can also allow for less sharpening.
A photo with fine lines...like maybe that of an oat field with many upright stems....can also be lessened. Again, it all takes practice.
If a newspaper image is running roughly at 200 line screen, you can increase amount of sharpening.
If the image is grainy, try setting your threshold to higher numbers like 15 or 20 to lessen grain effects. Monitors show things best when you are viewing your image at 1:1 ratio. Your monitor will probably show a bit of over sharpening, but this is ok because by the time it gets to output, you'll have a little dot gain to deal with which will soften the image a tad to look about right.
If you resize an image after applying the USM, you will degrade the image.
PHOTOS:
--First, convert your image to LAB Mode. Image>Mode>Lab Mode.
--Once there, choose the LIGHTNESS Channel--click on it once. You get there by going to Window>Show Channels if you don't find it on your own.
--Once you've clicked on the Lightness Channel, then go to Filters>Sharpen>Unsharp Mask. When you click on USM, the box pops up for you to make your selections as noted above.
There is no color in the Lightness Channel, so you don't have to worry about losing any of that. The color info remains unchanged...you are only sharpening the structure of the image.
You can check the Preview box while making your settings so you can see how things change as you move your sliders around.
If a photo is grainy, you can use the Despeckle Filter to lessen the grain, but do this before using the USM filter.
So, that's the scoop..... practice away!
Carolyn
Carolyn
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