A possible complication lies in the fact that the graininess of the final picture, a positive, is actually a map of the spaces between the grains of the negative.

Many times when I have looked at a very dense part of a negative through a grain magnifier on the baseboard of an enlarger I've remarked on the smoothness of the view. It's mostly dark with bright points here and there but I know those few widely separated "stars" will deliver conspicuous pepper 'n salt grain in the highlights of my final photograph.