Hi, I've been googling around for how LR or PS performs contrast enhancement and sharpening, but the web is conspicuously scarce when it comes to details about this. Just based on the available sliders in LR, it's tempting to draw the following (very broad) conclusion: Sharpening: When holding the ⌥-key and dragging the radius slider one is presented with what looks like a high frequency version of the image. It's therefore tempting to assume that sharpening is done by performing frequency analysis, adjusting how many pixels "away" from the high frequencies one wants to affect (the radius), and then specify the luminosity adjustments for those pixels (amount). Contrast: Based on the various descriptions on how contrast and sharpening works, it seems like they target pixels with different luminosity values. So maybe they increase contrast by adjusting the luminosity relative to the average luminosity? Or maybe relative to the average luminosity of the lower frequencies? Can anyone provide some details here? Am I totally on a wrong track here?