ACR is the built in raw editor in photoshop, it's refered to as a plug-in but it is built in. You can add other plug-ins to do all kinds of things, think of them as a filter (thats where they usually show up)
ACR can be used for editing jpegs and tiffs as well as raw file.
Radius is essentially how many pixles are "sharpened" each side of an edge. Amount is how much "sharpening" is applied.
Glad to help.Thank you, Wayne.![]()