 Most digital sensors are arranged in a rectangular grid pattern, making certain images (for example of parallel lines) susceptible to moiré pattern artifacts.Film is not affected by moiré because of the random orientation of the silver salts in its emulsion, however the pattern of these silver salts may become visible upon enlargement, creating the patterns called "grain" in the final output.The resolution of film images depends upon the area of film used to record the image (35 mm, medium format or large format) and the film speed.