If you’re looking into buying your first prime lens it’s probably because you’ve had some practice with the standard kit and you’d like something faster. What that means is a lens with a big aperture that allows you to shoot in darker settings without losing detail in the shadows.
The prime lens you choose will be determined in part by the camera system you’ve bought into.
Price, quality and number of lenses available vary a little, but primes come in a set of standard focal lengths whether you own a Nikon DSLR or a Panasonic mirrorless camera.
Unless you own a camera with a full frame senor, the image projected on to your sensor will be cropped. At the beginning of a photography course like those offered at the London Institute of Photography you’ll learn more about sensor sizes and why they’re important.
Each lens series has been designed to give you the same field of view relative to crop.
Standard focal lengths (in full frame terms)
9mm: extreme wide angle – fisheye view
18mm: standard wide angle
35mm – 55mm: normal field of view (what our eyes see)
85mm narrow field of view (great for bringing a subject forward)
On the Micro Four Thirds system (Panasonic and Olympus) where the crop factor is x2 relative to full frame, a 25mm lens is equivalent to 50mm on a full frame senor. Panasonic and Olympus have a range of primes that fit into the standard focal lengths listed above. Olympus makes a 17mm equivalent to 34mm, Panasonic has a 20mm pancake equivalent to 40mm.
Both manufactures make variants of the 50mm. This lens is also known as a nifty fifty because 50mm lenses are generally cheap to manufacture and wide enough for a standard field of view, while narrow enough to create a nice depth of field. Basically, a very versatile focal length for many situations.
Remember that a prime lens is going to limit you to a single focal length, no more zooming in or out to capture your shot. With all the options available, choosing just one comes down to your shooting preferences. If you’re having trouble deciding on the best field of view, think about what you want to shoot.
Holiday snaps and family portraits – 18mm, 35mm, 50mm
Landscapes – 9mm, 18mm, 35mm
Street photography – 18mm, 35mm, 50mm (although you may find the 50mm a bit narrow)
Portraits – 35mm, 50mm, 85mm
Sports and wildlife – 105mm+ (to capture the scene from a distance)
Just a quick note. Although the 18mm might seem equally versatile, the wider angle will give you less depth of field which might not be optimal for portraits where you want your subject to really stand out from the background.
There is no right lens, but there is good glass. Don’t worry about spending more on a better prime when you’re just getting started. Think about the focal length that will capture the kind of photography you’re interested in.