So if you are saying to change the "Sharpness" in all settings (Standard, Vivid, Landscape, etc) to +6, will there be any difference in selecting one vs another when shooting? I haven't gotten my D5300 out to look at this Menu, so I could very easily be missing something.
Well most Nikon cameras have "Picture Controls". On my D7100 I can choose from Standard, Neutral, Vivid, Monochrome, Portrait and Landscape in the Picture Controls menu. Each of these Picture Control presets have their own adjustments to Hue, Contrast, Brightness, Contrast and Sharpness (the details of these settings are explained in the manual. The Sharpness setting, as set by the factory is very, very low and I always suggest moving that particular slider to +6.
There's only one Picture Control setting I don't increase the Sharpness on, and that's Portrait. If you want to adjust other settings in these Picture Controls you can (I make a couple very minor tweaks to Standard and Landscape) but these are personal preference tweaks we're talking about.
I hope that answers your question.
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