What is the function of a camera's viewfinder?

The viewfinder of a camera plays a crucial role in helping photographers compose and frame their shots accurately. It provides a preview of what the camera lens will capture, allowing the user to see the scene with the same perspective as the lens. This is especially important in ensuring that elements within the frame are positioned as desired, helping to create balanced and visually appealing compositions.

By using the viewfinder, photographers can make adjustments to their framing before taking the shot, which is essential for capturing moments in a way that conveys their intended message or aesthetic. Whether using an optical or electronic viewfinder, this component enables users to focus on their subject while keeping an eye on the surrounding context of the image.

The other choices do not accurately describe the primary purpose of the viewfinder, as it is not used for providing additional lighting, adjusting ISO settings, or enhancing image quality directly; rather, its main function is to assist in composing the image prior to capture.