Sunday, January 24, 2010
Zoom lenses vs primes
Back when I first started photography there wasn't a hell of a lot of talk about megapixels :) There was a lot of talk, however, about the benefits of using prime lenses over zoom lenses.
In those days zoom lenses were a lot slower and the quality was certainly a bit dodgy. But they had some advantages, one of them being that you could change your focal length without having to actually physically move forward or backward.
Now if you're in a studio or somewhere where there's a lot of space around you to move then that's probably not much of a concern. But when you're 15 feet above the ground on the back of an elephant and there's a very large rhinoceros at your feet - well you can't move much, the elephant probably doesn't want to and the rhino definitely doesn't. (actually we heard a rumour he was chained there for the benefit of tourists! Just joking)
This was taken in Royal Chitwan National Park in the Sauraha region of Nepal. It was my first time out on elephant back and I wasn't really sure how close we could be expected to get to the animals so I put my 400mm on - just to be safe. Well as you can see it got me very, very close. Probably a little too close for my liking. I would have liked to have had a bit more room to move and so a zoom would have been a lot better in this case.
With the modern zooms being not only fast (the expensive ones are all a constant f2.8) but incredibly sharp, for the travelling photographer there's probably not much need to use prime lenses unless they're specialty ones. Some photographers swear by their 85mm f1.2 lenses for their shallow depth of field and beautiful portraits, others carry a small, fast 50mm for dark situations. But as our cameras go to higher and higher ISO's with hardly any noise the argument for needing a fast lens for darker situations is rapidly becoming a thing of the past.
With your zoom lenses the faster you can afford the better. And the longer the lens the faster you want it. So for a wide-angle zoom you might be able to get away with a slower lens (say f3.5 to f4.5) but as your lenses get longer the extra light gathering capabilities of faster lenses (f4 or f2.8) will be worth their weight in picture opportunities. Many travel photographers (including myself) carry a kit of 3 zoom lenses - super wide-angle (16-35mm), medium zoom (28-70mm) and telephoto zoom (70-200mm).
Oh and I still carry my 400mm wherever I go -just in case I run into another chained up rhino!