The Camera Lens -- Zoom Vs. Prime
The first thing you need to decide on when buying or setting out to use a lens is whether you want a zoom lens or a prime lens. That is, a lens with only one fixed focal length. Zoom lenses may look like the obvious choice for many, since you'll get all the different focal lengths it covers in one-and-the-same lens. It is very flexible and you don't have to carry extra lenses and waste time swapping from one lens to the other. Want to capture the grand landscape? Zoom out and click. Want to capture someone's face expression? Zoom in and click. These are definitely big advantages over prime lenses, where you're stuck with the same focal length. But prime lenses have their advantages too. Generally speaking, they're smaller, faster, cheaper, sharper, have less distortion and are less prone to damage than zoom lenses. Worth considering suddenly, aren't they? Let's have a more detailed look at the primes.
A fast lens, you say?
Prime lenses don't use as many lens elements (layers of glass) inside them as zoom lenses do. And that's the key, they are more simple constructions and hence smaller and cheaper. Now what's this about primes being fast? It's still a piece of glass, right? Not a racing car! Well, when photographers talk about a lens being fast, it's actually a bit of nonsense. What they should be saying is that the lens has a big aperture which allows for more light to pass through the lens, thus allowing the camera to nail the correct exposure faster. It's just easier to say that ‘the lens is fast!'. Using one of these ‘fast lenses' gives you a few extra possibilities. You can easier freeze and capture high-speed action situations (big aperture and short shutter speed) and you can easier take hand-held pictures in low-light conditions (big aperture and longer shutter speed). Just notice that when you're using a big aperture, the area of sharpness (the ‘depth of field') becomes smaller. Things in front an behind of your focus point will be rendered unsharp. That's not necessarily a bad thing though, it can help to attract attention to the main subject of your photo and away from any background clutter. The larger the aperture and the larger focal length you use, the smaller your focus area will be.
But back to prime lenses being simple constructions, their other advantages I mentioned above were their superior sharpness and less distortion. Especially the sharpness can be useful to you if you plan on submitting photos to a stock agency. Selling 10 to 20 Mega-pixel photos requires excellent performance from your lens.
And finally, because prime lenses can't zoom, there's one less thing that can break!
Choosing between zooms and primes isn't always that simple. Furthermore, some people feel that the single focal length of primes restricts them while others find it liberating that they have that one thing less to think about. Personally, I use both zooms and primes. When I'm in a fast-changing situation with things happening all around me, I prefer the flexibility of the zoom. But when I go out on a shoot with a special expression in mind, I prefer to use the appropriate wide or long prime lens.
A fast lens, you say?
Prime lenses don't use as many lens elements (layers of glass) inside them as zoom lenses do. And that's the key, they are more simple constructions and hence smaller and cheaper. Now what's this about primes being fast? It's still a piece of glass, right? Not a racing car! Well, when photographers talk about a lens being fast, it's actually a bit of nonsense. What they should be saying is that the lens has a big aperture which allows for more light to pass through the lens, thus allowing the camera to nail the correct exposure faster. It's just easier to say that ‘the lens is fast!'. Using one of these ‘fast lenses' gives you a few extra possibilities. You can easier freeze and capture high-speed action situations (big aperture and short shutter speed) and you can easier take hand-held pictures in low-light conditions (big aperture and longer shutter speed). Just notice that when you're using a big aperture, the area of sharpness (the ‘depth of field') becomes smaller. Things in front an behind of your focus point will be rendered unsharp. That's not necessarily a bad thing though, it can help to attract attention to the main subject of your photo and away from any background clutter. The larger the aperture and the larger focal length you use, the smaller your focus area will be.
But back to prime lenses being simple constructions, their other advantages I mentioned above were their superior sharpness and less distortion. Especially the sharpness can be useful to you if you plan on submitting photos to a stock agency. Selling 10 to 20 Mega-pixel photos requires excellent performance from your lens.
And finally, because prime lenses can't zoom, there's one less thing that can break!
Choosing between zooms and primes isn't always that simple. Furthermore, some people feel that the single focal length of primes restricts them while others find it liberating that they have that one thing less to think about. Personally, I use both zooms and primes. When I'm in a fast-changing situation with things happening all around me, I prefer the flexibility of the zoom. But when I go out on a shoot with a special expression in mind, I prefer to use the appropriate wide or long prime lens.
