I have both and use the lens caps more then the tubes. With the caps your auto sensors still work (ie auto f-stop, focus). With the tubes at least the cheap ones I have you have to adjust everything manually. Other then that are almost the same. With the tubes you get a slightly better image, not a mirrored image like you get with the caps. If you want you can try mine out before you waste any money, that is if you have a nikon.