Relatively insensitive film, with a correspondingly lower speed index, requires more exposure to light to produce the same image density as a more sensitive film, and is thus commonly termed a slow film. Highly sensitive films are correspondingly termed fast films. In both digital and film photography, the reduction of exposure corresponding to use of higher sensitivities generally leads to reduced image quality (via coarser film grain or higher image noise of other types). In short, the higher the sensitivity, the grainier the image will be. Ultimately sensitivity is limited by the quantum efficiency of the film or sensor. COUNT 5
QSN1 What does the film's quantum efficiency limit?  ANS1 sensitivity QSN2 What speed of film is produced by insensitive film?  ANS2 slow film QSN3 What leads to lower quality images? ANS3 reduction of exposure QSN4 What types of film are considered fast films? ANS4 Highly sensitive films QSN5 What effect does highly sensitive film have on images? ANS5 reduced image quality