The sensitivity of the film is ISO 400 (27°). However, its high flexibility in terms of light sensitivity also allows you to set your camera to ISO 200 (24°) and ISO 100 (21°). This gives you more options for experimentation in different lighting conditions. Green tones will become a shiny purple when you use an ISO 100 setting, but with an ISO 400 setting greens will instead become a darker indigo. This gives you the opportunity to create everything from soft lavender hues to the most vibrant violets.