And you dont need to push smart sharpen to 10 when you actually use enough usm. So, radius 2, strength 130% (75% faces), equalizer 70%, smart sharpen 5, interpolation Max / High / Vector. would be a good place to start for a 4x6. Slowly getting there, its all starting to make a little sense at least.
First of all you are making good progress!
Unless you are shooting in RAW mode, not all images need the same amount or any sharpening. So you do it by eyeball.
It depends on the scene and the F stop and the quality of the lens.
Smart sharpen to default (5)...USM settings check and recheck as you experiment....Interpolation is correct...... I would use HYBRID as the interpolator, but Vector is good too.
Here's a basic explanation of the Equalizer. Again not every shot needs the equalizer, but you try and decide yourself when and how much!
Sharpening is really the increase of contrast on objects with edges of some
sort; e.g. grass, trees, pebbles, anything like that.
When using USM in a normal fashion, you realize the grass and trees look
fake when you reach a certain degree of USM.
When you add the EQ, the focus or strength of the sharpening lessens on the
edges and allows the softer items like flamingo feathers, even some faces, to continue to get
sharpened without over sharpening the edges part.
It makes a 3D effect when you get it right!
It works!!
I used flamingo feathers as an example, (living in sw florida) because they are very soft and smooth. Pelican feathers are the opposite. They have all hard sharp edges and will over sharpen easily.
So play with the controls and gain experience.
If you want to try Hybrid, simply click on EDIT and Interpolation (top selection) and select Hybrid.
Never asked what version of Qimage you were running. Hopefully, you are up to date.
Fred