Ok well I know I should know these answers by now but I dont so I am going to ask them anyway lol. I need a lens that I can zoom in closer to the subject I have the Nikkor 70-300 But I find myself needing to get closer.. Now this is a really stupid question, why does it seem like some of the 250-300 lenses are so big? Does it make a difference how big the lens is apposed to the mm? Also what do Teleconverters do? One more stupid question? Why do I see so many people with battery grips on their camera I seem that I can shoot an entire day and my battery is perfectly fine when I am done.. is there an upside to the batter pack?