Sharpening Photos: Amount, Radius, Detail, Masking

Sharpening does not create detail. It increases local edge contrast, which is called acutance, and that makes existing edges read as more defined. The distinction matters because it defines the limit of the tool: no amount of sharpening will rescue an out-of-focus shot or motion blur, it will only make the blur look crunchier. If a file is soft because of focus or shutter speed, the honest fix is a reshoot, not a slider.

There are two separate sharpening stages and they are not interchangeable. Capture sharpening happens in the RAW editor and is mild. It counteracts the slight softness introduced by the sensor and its anti-aliasing filter, and it is applied at full resolution. Output sharpening happens at the very end and is tailored to the final size and medium. A screen image needs less; a print needs more, because ink spreads slightly on paper and softens fine detail. Never sharpen once for screen and then send that same file to print.

The four sliders describe a shape, not just a strength. Amount is how much edge contrast you add. Radius is how wide the halo around each edge becomes: roughly 0.5 to 1.0 for fine detail, 1.5 to 3.0 for broader structure. Detail controls how much halo suppression happens at the edge. Masking decides where any of it applies at all. Use masking while holding Alt or Option so that only edges are affected and smooth areas like sky, water, and skin are skipped entirely, which also hides noise from the sharpening pass.

Portraits usually want a low amount, a radius near 1.0, and heavy masking. Landscapes and product shots tolerate a higher amount with a radius around 0.8 to 1.2 and moderate masking. The familiar failures are white halos along high-contrast edges, crunchy over-sharpened foliage, sharpening the noise in a high-ISO file, and re-sharpening a JPEG that the camera already sharpened. Always judge the result at 100 percent zoom, never on a fit-to-screen preview.