Extension tubes are a set of hollow, light-tight tubes of varying lengths that fit between a camera body and lens to increase the distance between the lens and the film or sensor. This additional separation allows the lens to focus closer than its normal minimum focusing distance, effectively enabling macro or close-up photography without the need for a dedicated macro lens. By combining different tubes or using them individually, photographers can adjust the degree of magnification and achieve precise focus on small subjects.
Extension tubes are especially useful for photographing flowers, insects, or small objects where detail and sharpness are important. Because they contain no optical elements, they do not degrade image quality, making them an affordable and versatile tool for photographers who want to explore macro photography with existing lenses.