Anyone have this problem? I've just recently purchased a Sigma 18-200mm OS lens and I feel that my batteries are being burned up faster than when I only had my Nifty-50. I have read about turning off image stabilization because that eats up batteries. I believe this to be true because I left OS on the other day and I went through 2 batteries like nothing. Howerver, last night I was taking photos of the city. I was using between 2-20 second shots, had OS off and was using only manual focus. Again, I burned up my battery faster than when I was using the 50mm. So what is the deal here? Since only owning a prime prior this experience, does a zoom lens normally eat battery power faster than primes? Thanks in advance. Here is one of the shots I was taking last night.