According to Hertrich (2005), the details of the image are inversely proportional to the speed of the screen which therefore means that the slow detail screen has greater films than the fast intensifying screen. This is so because, in slow detail screens, the area that is exposed by each x-ray will be smaller and slower hence the details better. A reduction in speed increases the dosage of ionizing radiation. This, therefore, means that the fast intensifying screen uses a smaller dosage of ionization radiation compared to the large dosage used by the slower detailed screen. The slow screens are usually of the standard type while the fast screen has the rare earth type. The last characteristic is that a fast intensifying speed reduces patient exposure to the radiation while a slower detail screen increases exposure. As a result of this difference in image detail and exposure to the radiation, the slower detail screens are used to produce photo films while the fast intensifying screen is used for medical purposes.