I have been thinking about getting a battery grip for my 40D. But I was wondering if anyone could enlighten me with an example of a time that, say, if you didn't have it you would have run out of juice and missed shots etc. In other words, what are the advantages or reasons that might help me decide whether I need it.
I have had my 40D out for say 12-14 hours and took 1000 pictures... and at the end of the day, the lowest I have seen my battery is around 35%. So I am just wondering what the real utility is?




