The best portrait lenses for Nikon
Now that our portrait guide on page 16 has inspired you to shoot more portraits, you may be evaluating your kit’s suitability. Kit lenses are suitable for a wide range of subjects, but alas, portraiture isn’t one of them; with a widest available aperture of f/5.6 at the long end of the zoom range, they simply can’t give you the tight depth of field that you really need for portraits, for blurring the background and making the person you’re shooting really stand out.
Even a top-end standard zoom with an f/2.8 constant aperture can leave you wanting a little more when it comes to limiting depth of field. And while some find a fast telephoto zoom a viable alternative for portraiture (see our Head to head on page 86), the sheer size and weight of a 70-200mm f/2.8 lens certainly isn’t ideal. Yet another option is to go for a ‘portrait macro’ lens that has a suitable focal length. But, again, the widest available aperture there is usually a still-limiting f/2.8.
The best portraiture solution is to add a fast prime lens to your D-SLR outfit. For FX (full-frame) cameras, the classic focal length of 85mm enables you to shoot head-and-shoulders or halflength portraits from a natural distance, without invading your subject’s personal space. If you’re using a DX-format camera with a 1.5x crop factor, a ‘nifty fifty’ lens will give you a similar effective focal length of 75mm.
There’s a variety of 50mm and 85mm portrait-friendly prime lenses on the market, typically with a widest aperture of f/1.8 or f/1.4. Compared with the f/5.6 aperture of a standard zoom, these have an aperture rating that’s 3.33 or four full stops faster, respectively. Faster shutter speeds can be a bonus, especially for indoor portraiture or when putting your subject in the shade to avoid the glare of the sun, but it’s the tighter depth of field offered by wide apertures that’s the main attraction.
How sharp should you go?
Corner sharpness is of little importance if you’ll be blurring the background of portraits, and vignetting at wide apertures can actually be an added attraction. Even extreme centre sharpness might not be highly desirable, as it’ll show up every wrinkle and blemish. There’s something to be said for a lens that smooths over the cracks at wide apertures, to give a more dreamy look to portraits. Even so, you might prefer to capture as much sharpness as possible in the eyes, and it’s certainly easier to add smoothing at the editing stage, rather than trying to inject some sharpness that simply isn’t there.
Whatever your take on image sharpness in portraits, the bokeh of a portrait lens is often more important. Bokeh is a subjective measure of the pictorial quality of defocused areas within an image, which should be smooth and creamy. The transition between focused and defocused areas should be smooth too. Fast lenses can also be afflicted with increased longitudinal chromatic aberrations and coma (see jargon buster, below).
From a budget point of view, f/1.4 lenses are typically more expensive than their f/1.8 counterparts. The forward elements in a faster lens need to have a larger diameter, to let in more light, so faster lenses are bigger and more expensive to manufacture. However, the quality of glass and construction can still be just as good in ‘slower’ lenses, or maybe even better. The two Tamron lenses on test aim to keep size and weight to easily manageable levels with a modest f/1.8 aperture rating, while also adding optical stabilisation, which is practically unheard of in portrait prime lenses.
Faster shutter speeds can be a bonus, but it’s the tighter depth of field offered by wide apertures that’s the main attraction