Marrant, ce post est en total contradiction avec l'article de kenrockwell.com, qui dit :

Try shooting your 5D Mark II at it's M (11MP) or S (5MP) settings. If you look at your images at 100%, you'll see that the lower resolution shots are sharper!

Why? Because they use less, or no, Bayer interpolation. No digital camera really resolves its rated resolution; they cheat and interpolate up, so at 100% at its rated resolution, no digital camera image is as sharp as a true scan from film.

At the 5MP setting, you have 100% R, G and B pixels, exactly as if you were using a Sigma Foveon sensor. If Sigma was selling this, they'd sell the 5MP (S) setting as if it were 15MP (also a lie).
Autrement dit, selon l'article, plus l'on choisi une résolution basse, plus les images sont piqués (!), du au fait qu'en mode S (5MP), il s'agirait de la résolution native du capteur, alors que les résolutions supérieures ne seraient que des interpolations.
Ce mode S "reviendrait donc au même" que le fameux capteur Foveon de Sigma.