In the old days fixed length lenses, or primes, such as 50mm, 300mm, 500mm were considered the norm as they offered better quality and performance than zoom lenses. Now the situation has reversed entirely and we consider zooms to be equal to fixed lenses and to win over them in terms of flexibility. Another consideration is weight of course, airlines are getting tougher and tougher with the weight of cabin baggage, so having one lens that can do the same job as three is a major advantage for any traveller.
Still not convinced zooms are better? Well consider this. What makes a good picture stand out from a bad one? Light, of course, as you cannot cheat light. But I sincerely believe it’s composition that really makes a picture come alive by telling a story and making the individual elements work together. Composition allows you to take the picture as you want it to be seen, it’s what really separates a good photographer from a lazy one I think. Of course you can do a lot of compositional adjustments on the computer later on, provided you know how, but I still think you need to get the basic composition right “in-camera”. Using a fixed lens like a 300mm fixes you to one composition, you are not free to move backwards and forwards to fit bits in, whereas with a zoom it’s just a quick twist and it’s done.
There is one final reason to use zoom lenses in Antarctica. A lot of your photography will be from a small Zodiac, with 10-12 other photographers in it too. Trying to keep a long fixed lens stable in these conditions, without decapitating your fellow passengers when you swing it round, can be tough. Every time I have shot in these situations, whether it be from Zodiacs in Antarctica, the Arctic or Galapagos, I use a zoom lens. It just makes sense.