What is the overall resolution of an imaging system the product of?

The overall resolution of an imaging system is closely tied to the concept of the modulation transfer function (MTF). MTF quantitatively describes how well an imaging system can reproduce (or transfer) various levels of detail from the object being imaged to the resulting image. It essentially represents the system's ability to resolve different spatial frequencies, indicating how contrast varies with different levels of detail.

High MTF values at higher frequencies indicate the system can accurately depict fine details, contributing significantly to the perceived resolution of the final image. Therefore, when assessing an imaging system's resolution, MTF serves as a crucial measure that encapsulates various factors, including pixel size, system noise, and geometric accuracy, all of which contribute to the clarity and detail observable in the images produced.

In contrast, while frequency, resolution, or number of line pairs/mm are all important concepts in imaging, they do not holistically account for the overall resolution independent of the specific characteristics of the imaging system like MTF does. Thus, the modulation transfer function is the most comprehensive and correct answer for determining the overall resolution of an imaging system.