Electronic Enhancement
The following images, from two different scanners, shows the impact of electronic enhancement within the scanning process.

The image on the left is from a well known scanner, and shows what looks like excessive electronic aperture enhancement (electronic frequency enhancement) to increase the perceived resolution of the image. The image to the right is from Cintel's diTTo, and shows less obvious artefacts.

Both images have been cropped from their respective original frames and subjected to the same (limited) processing to display them here, so any artefacts introduced by displaying them here would be identical for each image.

Diffuse Light Source
The following images show the effect of different light sources on a surface scratch on the film's emulsion.

Again, the first image is from a well known film scanner, and due to the 'parallel' light source used shows the light scratch on the film's surface.

The second image is again from Cintel's diTTo scanner and shows how it's use of a more diffuse light source effectively masks the surface scratch, without any electronic touch-up or repair.

Notice also the more apparent grain within the top image, due again to the less diffuse light source being used.

The images also show a difference in the 'calibration' of the respective scanners, with the first having more contrast applied, giving the illusion of potentially having better resolution, although the lower image does show more blue saturation too.