Often it is desirable to sharpen only portions of an image while leaving the majority of the image unchanged.  Using the lasso tool to select the portions of the image to be sharpened and applying unsharp mask to these areas is one way to do this.  A more precise method is to use layers and a layer mask to select the areas to be worked on.  This technique allows one to exercise a great deal of control during the sharpening process.  I've developed a tutorial to demonstrate this technique using the Paint Shop Pro image-processing program.

My demonstration tutorial of the technique is scaled for a browser resolution of 1024 X 768.  If you are using Internet Explorer for a browser, I suggest pressing F11 before starting the tutorial.  This will allow the browser to show the tutorial without having to use the scroll bars.  After the tutorial finishes, press F11 again to restore the browser display to normal.

Dave Street, using a TAKAHASHI FS60C refractor telescope and the Starlight XPRESS HX916 camera, captured the image used for the demonstration tutorial.  The FS60C was piggybacked on a 10-inch Meade LX200GPS telescope. He used a Meade DSI camera and the LX200GPS to autoguide the exposure.  My thanks go out to Dave for his gracious permission to use his image for this tutorial.