High Pass Filter Sharpening in PhotoShop
Don Goldman and Ken Crawford conducted a presentation of the High Pass Filter sharpening routine at the 2004 AIC conference. This procedure allows selective sharpening of parts of an image. This technique allows a great deal of control of the sharpening process to be achieved. The routine may be applied only to areas of interest in the high signal to noise portions of the image. This avoids introducing sharpening artifacts, common with other sharpening routines, being introduced in the low signal to noise areas of the image.
The image used for the demonstration tutorial was captured by Dave Street using a Takahashi FS60C at f/4.4 and a the Starlight Xpress HX916 camera. The FS60C was piggybacked on a 10-inch Meade SCT. He use a Meade DSI and the SCT to autoguide the exposure. My thanks go out to Dave for his gracious permission to use his image for this tutorial.
My demonstration tutorial of the technique is scaled for a browser resolution of 1024 X 768 for presentation. If you are using Internet Explorer for a browser, I suggest pressing F11 before starting the tutorial. This will allow an expanded browser window 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 and then use the "back" button to return to this page.
To start the tutorial click here.
A PDF file listing the steps for the High Pass Filter Sharpening technique may be viewed here.