Thanks Chris
Took a while to track down on the Adobe site. The Windows version is
HERE and Mac
HERE
And a brief extract from the readme file:
Clarity
New Control available in the Basic panel. Clarity adds depth to an image by increasing local contrast. When using this setting, it is best to zoom in to 100% or greater. To maximize the effect, increase the setting until you see halos near the edge details of the image, and then reduce the setting slightly.
Sharpening Improvements:
Additional controls available in the Detail panel. The zoom level must be set to 100% or greater in order to view the effects of these controls.
Amount
Adjusts edge definition. Increase the Amount value to increase sharpening. A value of zero turns off sharpening. In general, set Amount to a lower value for cleaner images. The adjustment locates pixels that differ from surrounding pixels based on the threshold you specify and increases the pixels’ contrast by the amount you specify. Press Alt (Windows) or Option (Mac OS) while dragging this slider to view the sharpening on a grayscale preview.
Radius
Adjusts the size of the details that sharpening is applied to. Photos with very fine details may need a lower radius setting. Photos with larger details may be able to use a larger radius. Using too large a radius will generally result in unnatural looking results. Press Alt (Windows) or Option (Mac OS) while dragging this slider to preview the radius effect on edge definition.
Detail
Adjusts how much high-frequency information is sharpened in the image and how much the sharpening process emphasizes edges. Lower settings primarily sharpen edges to remove blurring. Higher values are useful for making the textures in the image more pronounced.
Masking
Controls an edge mask. With a setting of zero, everything in the image receives the same amount of sharpening. With a setting of 100, sharpening is mostly restricted to those areas near the strongest edges. Press Alt (Windows) or Option (Mac OS) while dragging this slider to see the areas to be sharpened (white) versus the areas masked out (black).