Final answer:
The smaller the ISO number, the less sensitive the air is in photography.
Step-by-step explanation:
The ISO number in photography determines the sensitivity of the camera sensor to light. The smaller the ISO number, the less sensitive the air is.
For example, an ISO of 100 is less sensitive to light than an ISO of 800. Lower ISO values are ideal for situations with ample light, such as sunny outdoor scenes, while higher ISO values are necessary in low-light conditions.