How does the exposure time of a two-film packet compare to a one-film packet?

The exposure time for a two-film packet is the same as that for a one-film packet because the amount of radiation required to create an image does not change based on the number of films in the packet. Each film in the packet is exposed to the same x-ray beam, and thus the exposure time remains unchanged regardless of whether there is one film or two films.

This means that the films can be processed individually, and each will develop an image based on the same exposure time. The sensitivity of the films and the x-rays used remain constant, ensuring that the exposure parameters do not vary with the number of films present. Therefore, the exposure time for a two-film packet is appropriately considered the same as that for a one-film packet.