I do not understand how to use the highpass filter adjustment in NX2. When is this more appropriate (perhaps should it always be used?)and does one use in conjonction but prior to the other sharpening adjustment tools?
Next, when I click the highpass filter adjustment the image goes to grey, I use the slider to bring out some definition, but I can never get the image back to color. What do I not do correctly or not understand?
#1. "RE: How to use the highpass filter sharpening tool?" In response to Reply # 0 Mon 24-Sep-12 04:43 PM by DeanAZ
Howdy William. The proper way to use this tool is to use the blending mode set to Overlay in the Opacity settings. This will have the effect of blending the effect you are seeing (mostly gray with the edges enhanced) and the background image to allow for the sharpening of details larger than the pixel value selected. Remember you can use a brush to apply the sharpening effect only to the areas you want or use color control points to include or exclude parts of the image from the sharpening step.
It is good to use where you want to emphasize fine detail without sharpening noise as would be the case with the standard unsharpen mask that is also available. In general I only apply a small amount of sharpening as part of the picture control and save any sharpening for the end of my processing steps once I know what my target is for the image. The amount and type of sharpening is highly dependent on the final size of the image and the viewing method. Are you printing, at what size, etc.?
Give it a try. There are lots of sharpening tutorials available.
#2. "RE: How to use the highpass filter sharpening tool?" In response to Reply # 1 Mon 24-Sep-12 04:56 PM by William Rounds
Thank you for bringing the blending overlay aspect to my attention. I did not know that. But once I do use the slider for say 2.5 px, at what point do I see the image return to a color image? When I hit the "next step" button my image is still grey.
#3. "RE: How to use the highpass filter sharpening tool?" In response to Reply # 2 Mon 24-Sep-12 06:14 PM by DeanAZ
I keep the blending mode at Normal while adjusting the pixels to see how strong of an effect I am creating but then I switch the mode to Overlay to see the results in color. I keep it in Overlay for the balance of the editing process.
Sometimes I set the effect with a higher pixel number than I actually need but then slide the opacity down from 100% to some appropriate value while I am looking at the image in color at 100% magnification.