Hi folks,
Having recently acquired Topaz Labs'
InFocus Photoshop plug-in I thought I'd do a side by side comparison with Photoshop's native "Smart Sharpen" filter. Photoshop offers a number of tools to sharpen images, as does Adobe Camera RAW, but Smart Sharpen has been my usual tool so, on a personal level, it made sense to use it as my benchmark when judging how well InFocus performed.
Update: Rather than just confine this thread to my own weapons of choice I've also provided a link to my starter image at the end of this post so feel free to download it and see how far you can push your own sharpening tools (without introducing too many artefacts) and share your best efforts.
As a starting point I took a 300 x 300 pixel crop from an image which contained the detail I wanted but which I knew wasn't pin sharp. The RAW file was developed in Adobe Camera Raw where I removed chromatic aberration and tweaked the exposure and colour balance but turned the default sharpening off. The resulting image, labelled "Original" is pretty soft. I sharpened the image separately, trying to use the most aggressive settings I could before those settings created what I personally considered to be unacceptable edge artefacts, using both Smart Sharpen (settings: Amount 56%, Radius 1.3px, Remove Lens Blur, More Accurate) and InFocus (settings: Blur Type - Out of Focus, Blur radius 0.80, Suppress artefacts 0.20, Micro-contrast 0.23, Sharpen 0.21, Sharpness radius 0.80). As an aside, the 56% Smart Sharpen setting is way more than I'd usually use but the crop was able to withstand it, something that wouldn't be true if anything in the frame had been sharp to start with! I've also included DeNoised versions (another Topaz Labs plug-in), using the same light RAW setting for the two images, as both tools create unwanted noise in the sky in particular. Here are the results as 100% crops presented as an animation to allow direct comparisons:

The effect is subtle but I prefer the output of InFocus which does a good job with the twigs against the sky but which also seems to bring out more detail in the background landscape and the flowers. To better see what's happening at the pixel level here are the 2x blow ups (nearest neighbour "interpolation") of the individual frames. Obviously at that scale things get quite ugly but I offer them solely so you can decide whether my choices would have been your choices in terms of what is or is not acceptable in the way of artefacts.
My normal workflow would be to allow ACR to perform default sharpening during RAW conversion, something that is pretty mandatory for anything that comes from a Bayer sensor fronted by an anti-aliasing filter, so I'll add a disclaimer that the "Original" image above should in no way be used to judge either the quality of the camera or the lens which was set to a fairly extreme 7mm focal length - 14mm equivalent FoV on a full-framer!
If you'd like to try your own settings (or tools) and share the results in this thread then you can download an unlabelled JPEG version of the original 300 x 300 pixel crop by clicking on
this link.
Bob.