Extension tubes are accessories used in photography to increase the magnification of a lens. They come in various sizes and can be attached between the camera body and the lens, allowing for closer focusing distances and macro photography. By using extension tubes, photographers can achieve greater magnification without the need for a dedicated macro lens. These tubes are often used by professionals and hobbyists alike to capture intricate details and close-up shots. If you are looking for affordable options, consider purchasing pre-owned extension tubes and lens accessories, which can provide excellent value for money while still delivering high-quality results.