[davidmanze]

When we talk about sharpness, we do not talk about details, we do not talk about resolution - sharpness is a term of it's own no matter what you try to define it with and also no matter what you "think" we're talking about   speak for yourself, but "we" as a number of people and me included are not confusing details with sharpness, even if we categorize a high resolving lens as "sharp".

 

Anyway, it is logically clear that a high resolution lens will appear sharper on a sharp edge - if there are sharp edges in a picture of sand, stone, grass or other highly detailed and structured scenes. But even if there's only one edge in a picture and no more details, we're still talking about sharpness. Imagine one single guitar string made of nylon, a couple of meters away from the lens - and nothing else but a flat, dark background with no visible structure: See? No details, but maybe sharpness.

 

Also, "sharpness" on a lens testing site has absolutely nothing to do with software algorithms, otherwise we would talk about applications. We take it for granted the lenses are tested in equal surroundments and with equal software parameters - boom, that's it. If the influence of software is the same, you can subtract it from the equation. For sharpness you need glass, light and a sensor and all of that of decent quality and mounted on something quite stable.

I think Toni-a is right in what she/he is saying!.................................... although maybe we ought to be talking about 'apparent sharpness'!

 

       PS's sharpening increases the contrast on the edges, this in reality doesn't change the detail or resolution but it 'does' appear sharper. In the case of a high resolution image from say a Zeiss Otus lens on a good sensor not much in the way sharpening is needed because edge sharpness is there already, but when we are not looking at edges but say at mass feathers, the 'detail' will be there plain to see, whereas the heavily sharpened first lower resolution image just won't have the fine detail in the feathers. 

  One other scenario, on say, a 4Mps sensor the edge blur will only be resolved over a pixel or two, on a 36 Mps sensor this edge blur will be spread over 9-18 pixels no prizes for which of the two sensors will produce the sharper edge here! 

  Lastly all this sharpening and processing come at a price, to reduce the artifacts that have appeared from this forcing the image, the whole lot has to be denoised with all the further degradation that entails, but strangely it can produce quite a sharp image with pop, just no genuine detail! I know I've done it with the 50-500 Sigma @ 500mm, blow it up to 200% + and you can see how!