What is spatial resolution?

• A. The maximum brightness of the image.
• B. The amount of noise in the image.
• C. The color depth of the image.
• D. How well small objects close together are revealed.

Answer: (D)

Spatial resolution is about how finely an image can represent detail. It describes how well two small objects that are close together can be seen as separate features. When the system has high spatial resolution, fine details and tightly spaced structures are distinguishable; when resolution is low, those nearby details blur into one. This limit comes from both the optics (lens sharpness and diffraction) and the sensor/sampling (pixel size and how the image is sampled).

This isn’t about brightness, noise, or color depth. Brightness refers to how light or dark the image is, noise is random variation that can obscure detail, and color depth is how many colors can be represented. Those factors affect different aspects of image quality, whereas spatial resolution specifically governs the ability to resolve small, closely spaced features.