On the Canon 7D, the in-camera sharpness setting does not change the underlying RAW image data. It mainly affects JPEGs, and it can also influence how the image preview looks in-camera or when first opened in Canon software.

So if you shoot RAW, sharpness at 0 vs 7 won’t permanently alter the RAW file itself. A high setting like 7 can look artificial because sharpening boosts edge contrast and can also emphasize noise and create artifacts.

There isn’t one “best” setting for everyone. For JPEGs, it’s a taste and subject-dependent choice: more sharpening can make edges pop, but too much often looks harsh. A moderate setting such as 2, 3, or 4 is a reasonable starting point, and some users find the 7D looks natural around 3. If unsure, it’s usually safer to use less sharpening in-camera, since you can always add sharpening later in post with more control.