Whether an extension tube is necessary or not depends on the context of the situation in which it’s being used. Extension tubes are typically employed in photography to enable closer focusing distances, effectively increasing the magnification of a lens without affecting the image quality like adding extra glass would. In scenarios where pulling out or slightly adjusting your current setup meets your needs—achieving the desired focus or getting the required shot—an extension tube may not be necessary. However, if you need to work with very close-up subjects and your existing equipment doesn’t suffice, an extension tube can be an affordable and effective solution for macro photography. The key is to determine whether the marginal benefits provided by the tube justify the purchase based on your specific photographic requirements.