So, I've heard that prime lenses produce better results. Obviously, zoom lenses aren't bad either, but how much difference is there? Does it make a difference in how wide the focal range is? For example, does a 70-200mm produce higher quality photos than an 70-300mm? The lens choices out there are mind boggling to a newbie like myself. There's a million different kinds in a million different focal lengths. I'm trying to figure out what lens or lenses I can afford and will be the best bang for my meager buck. Are Sigma and Tamron close to Nikon in quality?