In this video (start 6:00), The Topaz rep uses the Edge Softness slider to correct an artifact which he calls "ringing." Is this artifact the same kind you refered to as "...ringing artifacts, repeated edges of gradually lower amplitude"? If yes, why does he recommend the Edge Softness slider to fix it while you say to use the Supress Artifacts slider?
Yes, but the ringing is in a sense
caused by the overly sharp edges. So the Edge Softness control takes away the cause for the ringing, but it doesn't address the ringing artifacts themselves. The Suppress Artifacts control does that, after the artifacts were already created. So the Softness control
prevents sharp edges that could cause artifacts, and Suppress Artifacts control reduces the artifacts that were already created.
It would help if I saw exactly the types of artifacts each of these sliders are designed to mitigate. How does "Ringing" look different from "stair stepping?"
Ringing looks like waves with repeating periodic brighter and darker patterns around high contrast edges and lines.
This document describes a method to detect and remove the artifacts, the images will show you some examples of ringing artifacts. Stair stepping turns a straight angled edge into a stepped (like stairs) edge with straight edge segments instead of a smooth continuous edge or line.
When you have trouble getting the correct settings in InFocus, start with the Sharpen panel settings maxed out for Micro contrast and Sharpness, and a Sharpness Radius setting of say 0.7 or 0.8 . Also set the Edge Softness and Suppress Artifacts sliders to their minimum. Now start with increasing the deconvolution method's radius slider while carefully avoiding double edges and ringing and stairstepping artifacts from appearing. The moment the artifacts are starting to show, use the Edge Softness control to reduce them again if in Estimate mode, and or use the Suppress Artifacts mode to take away the onset of the artifact generation. When in doubt, reduce the radius.
Only then adjust the Sharpness panel controls, sharpness radius first (usually smaller than the deconvolution radius), sharpness and micro contrast next, until you get an acceptable artifact free result. This way you are guaranteed artifact free results that will stand large format output without magnified artifacts.
Don't be surprised if your deconvolution radius settings turn out lower than they used to, because you are now no longer over-sharpening by using a too large radius. Also remember that InFocus is a Capture sharpening tool, not for Creative 'sharpening', that's where their 'Detail' plugin comes in.
Cheers,
Bart
