Extension tubes are one method of getting closer with EF lenses. A powerful tool when attached to standard and wide-angle lenses, they're also used with telephotos to get just a bit closer. With any lens, the longer the extension tube, the greater the close-up effect. The 12mm EF 12 II is often used with wide-angle lenses, while the longer EF 25 II is a better choice for normal or telephoto lenses. Auto exposure continues to work reliably, but manual focus is recommended in most instances. The version II extension tubes are also compatible with EF-S lenses.
