Lenses are often referred to as zoom or prime (or fixed). But what do those words mean? And how do you they affect your choice of lens?http://www.sydneyportraits.com.auhttp://www.greenwoodmedia.com.au
The terms prime and zoom refer to the focal lengths covered by the lenses.
Prime lenses are also known as “fixed” because they are fixed at a single focal length, in this case 90mm.
A zoom lens covers a range of focal lengths, for example 24mm to 70mm.
So surely, you’d go for a zoom lens over a fixed lens, given the flexibility it offers. Well, not necessarily. I use both my zoom and my prime lenses all the time and I couldn’t live without any of them, but I use them for different purposes.
Let’s start by looking at the advantages of a zoom.
— A zoom makes a great general lens. If you are going out during the day and don’t want to carry much gear, a camera and a 24-70mm lens, or something similar, will do you just fine, giving you wide, medium and long shots. Likewise, if you’re shooting at a party, the same set-up with a flash on top will generally do the job.
In these situations, using fixed lenses would mean changing lens a lot. In other words more gear, lots of fumbling and some missed shots.
A zoom is great for fast moving and unpredictable subjects. So for me, this means children, animals and sports. When shooting any of these things, I find it’s best to stay in roughly the same spot and allow the action to happen in front of me. Let’s say I’m shooting a toddler. Using a zoom allows me to capture close-up and wide shots as she runs back and forward, towards me and way from me. Generally zooming in and out will keep her in the frame. If I was to use a fixed lens I would have to crawl around on the floor after her and I’d still only get a handful of half decent shots.
So, the case for zoom lenses seems pretty convincing. So why on earth do I use fixed lenses?
Well, fixed lenses give me wide apertures. This is really important for two reasons:
First, it gives me a narrow depth of field. I can really blur a background - or foreground. I can keep the eyes in a portrait sharp while the ears and hair become soft. It’s a wonderful creative tool.
The other great advantage of a wide aperture is the way I can shoot in low light without ramping up the ISO and making the image all noisy. This is great for capturing natural or ambient light, whether it’s indoors with window light or using available light at night time. You can avoid using flash and really capture atmosphere in a way that’s difficult with a zoom.
Finally, a good prime lens will produce better quality images - sharper with better contrast, colour and bokeh (those pretty out-of-focus light splodges). If you’re still finding your way with photography some of these things will seem quite subtle at first but as your eye develops you’ll come to appreciate the difference.
Using prime lenses can mean switching lenses a fair bit. For this a lens belt is a good bet. It means all your lenses are right there in easy reach. No need to get a camera bag off your back and crouch on the floor.
So, what have we learnt? Zooms are better for moving subjects and for general outdoor photography. It’s fair to say a zoom - something around that 24 - 70mm area - is probably a good bet for beginners.
Fixed lenses are great for more advanced photographers who appreciate the difference in image quality and can make the most out of the extra aperture.
That said, I would recommend every photographer have at least one fixed lens - specifically a 50mm. You should be able to pick up a f1.8 50mm for around US$100. You’ll find it’s really sharp, has a nice wide aperture and is perfect for portraits.
So that’s it: fixed vs zoom. Please feel free to leave a comment - subscribe if you enjoyed the clip - and above all, happy shooting!