Hi, As I've begun to accumulate several lenses, I was wondering what is the best way to store them-- in a case, if you have one? If not, how? With the front element down, serving as the base? I think that's how, for example the 17-35mm case holds the lens... I just want to make sure I'm keeping them correctly. For most of the lenses, I have cases, but a couple, like the Tokina 11-16, which came without one, and for which I forgot to buy one, I keep it in its original box when I am not using it... Thanks for your help!