DSLR (digital single-lens reflex) cameras are becoming more affordable, and digital compact camera owners are making the switch to higher quality images.
One of the more common questions that comes up with the switch concerns the difference between lenses. Two of the most common types of lenses are zoom lenses and prime lenses. The difference between zoom lenses and prime lenses lies in focal lengths.
What is Focal Length?
A lens’s focal length is a measure of its ideal focus range for any given image, and determines the angle and zoom level of any given camera. Focal lengths are expressed in mm, and a rule of thumb is that a longer focal length results in a narrower “angle” of view and a higher zoom level.
As you can see, the 300mm focal length lens produces a larger, narrower-focus image than a 135mm lens at the same distance.
Difference between Zoom Lenses and Prime Lenses
Prime lenses come in one focal length only. There are dozens of different prime lenses, from wide angle to telephoto, but each focal length has to be purchased separately.
Zoom lenses, on the other hand, have a range of focal lengths (because they’re adjustable), and are very convenient because a photographer will never have to switch mid-shoot to another lens for a desired zoom level or perspective.
As you might expect, there are different reasons to use both prime lenses and zoom lenses.
The Pros of Prime Lenses
1. Quality – Since prime lenses are dedicated single-focal length lenses, they tend to be more powerful than zoom lenses that offer the same focal length. A zoom lens that offers 3 different focal lengths, for example, will not be as powerful or as reliable as 3 separate prime lenses.
2. Price – A single prime lens is always going to be cheaper than a zoom lens that offers several different focal lengths, because prime lenses have lower manufacturing costs than zoom lenses.
3. Speed – Image-capture is faster for prime lenses and slightly slower for zoom lenses due to their increased complexity. This is quickly changing, however, as zoom lenses improve.
4. Weight – One of the most common arguments is that a single prime lens will always weigh less than a single zoom lens. Zoom lenses are thicker, longer, and bulkier than prime lenses.
The Pros of Zoom Lenses
1. Portability – A counterargument to the weight argument is that multiple prime lenses will always weigh more than a single zoom lens. Not only will multiple prime lenses weigh more – they’ll also be more difficult to carry around.
2. One-time Payment – Similarly, 3 dedicated prime lenses are going to cost more than a single zoom lens that offers the same 3 focal lengths. A photographer that wants the same flexibility in prime lenses will have to pay more upfront.
3. Flexibility – The most compelling reason to buy a zoom lens is because it saves time and effort. Instead of switching between prime lenses mid-shoot, a photographer using a zoom lens can make quick adjustments on the fly.