I'm touching up photos for analysis, so they need to be as true to the original as possible (including when zoomed), but sharpened (anything from slightly to greatly) to bring out whatever textures, features and edges are possible. The originals might be faded, in poor lighting, soft focused, or lower-resolution so there's any number of causes.
If I use the unsharpen tools in a heavy-handed manner and sharpen them too much, the tool will create the appearance of textures and features that weren't actually present in the original subject matter of the photo. So there's a delicate balance.
My problem is that as I'm using the tool, I'm constantly trying to figure whether a photo would benefit from more of (or has too much of) "amount" and/or "radius". I can easily see if sharpening is overdone or not done enough, but when it comes to adjusting it, I'm spending ages experimenting with each slider in turn, trying to adjust one, then see if adjusting the other improves it, and so on.
I think that a big part of the problem is that I don't have much of a sense what the specific symptoms/differences would be, to distinguish over/underdoing "amount" vs. over/underdoing "radius". So I can't look at the photo and immediately work out which of the two settings it is, that's likely to be more mis-set, to get the sharpness closer to how I would like it.
Does anyone have any hints about the difference between how the two settings affect photos, and how I can approach this more methodically, or what to look for as guidance/symptoms, to figure out quicker which of the two settings for the tool is more relevant to an under/over sharpened picture, so I can cut down my trial and error attempts, or approach sharpening a poor photo in a more effective way?
Thanks for any help on this, it comes up a lot!