What's a "prime" lens and why should I
almost every lens that comes with a digital camera is a zoom
lens. It can change its angle of view to get more into the
photo (that's a wide angle) or make subjects look bigger and
closer (that's a telephoto).
Here's a Nikon camera fitted with a 50mm
f1.4 prime lens.
A prime lens has a fixed focal length. It
doesn't zoom. But because it doesn't zoom it can give you
The Benefit of Smaller Size
An 18-270mm zoom lens, small as it is, is
a lot bigger than a fixed-focal length lens.
Benefit of Fast Glass
A ‘fast lens’ or a
lens that uses ‘fast glass’ is one that has a larger
aperture opening so it is capable of capturing light at a
faster shutter speed than a lens with a smaller aperture.
The term ‘fast’ is sometimes debated as hobbyists might
consider an f/2.8 lens to be fast whereas some professional
photographers consider an f/1.4 lens to be fast. A lens made
with what is considered ‘fast glass’ can be a real asset
when shooting in low light conditions, especially if you
wish to forgo flash.
There is a budgetary
consideration (read: it costs more) when purchasing fast
glass, so evaluating how often you will be in the position
to need this extra benefit is important. Many people who
shoot in the field, in specialty situations such as evening
wedding receptions, and in varied conditions find the
investment to be well worth it because they capture
countless moments they might otherwise miss. If such
conditions impact your ability to earn money so that you can
properly handle these situations, adding a fast lens to your
kit might be the one tool that boosts your portfolio and
The Benefit of sharper images
As good as most zoom lenses are today, the best prime lenses
can be even sharper. The zoom lens that comes with your
camera was designed to cost only about $100 when sold with
the camera - a remarkable bargain but not the highest
High-speed lenses even focus faster than others, a real plus
in low light.
The Benefit of a fuzzy
When used wide open - around
f1.8 or f1.4 - a lens has much less depth of field than a
lens set to a smaller lens opening. Zoom lenses usually have
a maximum aperture of about f5.6 when set to a 50mm focal
length. The fast prime lens can really throw the background
out of focus, concentrating the viewers' attention on the