I watched an episode of Human Planet for the first time this weekend (yes I've been living in a cave...) and I was quite intrigued by some of the behind the scenes footage they shared.
I did a quick Google search and came up with this document:
http://downloads.bbc.co.uk …hp_filming_techniques.pdf
Interesting point they made:
It was only very recently that the Natural History Unit stopped making landmark documentaries on old fashioned film. Ironically film cameras are so technically simple that they actually work very well in extreme environments.
I have to admit I was looking for a DSLR of some sort, but none were mentioned. 
