Bruno Grandino

The problem could also be the diameter of the aperture you're using. The smaller the pixels are the higher the chances of the image to become less sharp due to the higher diffraction smaller apertures produce if compared to bigger apertures. It means that the Airy disc would be bigger than the pixel itself which means that the surrounding pixel would be getting a little bit of the light that was supposed to hit the initial pixel. Input the camera and the aperture you were using on this calculator from Cambridge in Color to check if this is the case. https://www.cambridgeincolour.com/tutorials/diffraction-photography.htm I know there is not much you can do in this case due to the need of a broader depth of field but you would at least know whether this is causing the problem or not.