Macro badges are often slapped on lenses that offer a magnification factor of 0.5x or less. However, true macro lenses (or 'Micro', as Nikon calls them) deliver 1.0x, or 1:1, magnification. This means that if you photograph a small object at the lens' closest focus distance setting, it will be the same size as the image projected onto the camera's sensor.
A 1.0x magnification factor might not sound impressive, but bear in mind that this is on the sensor itself. When the digital image is viewed on a computer screen or turned into a photo print, there's the potential for enormous enlargement - levels of detail are revealed that are practically invisible to the naked eye.
To get full 1.0x magnification, you'll need a macro prime lens rather than a 'macro' zoom lens. Even then, some prime lenses bearing the macro designation don't give full 1.0x magnification.
All of the lenses we've included in this test fit the 1.0x criteria, but there are still some major differences between them.
The focal lengths of the lenses in our roundup range from 40mm to 105mm. Unlike some antiquated optics, all modern macro lenses are dual-purpose designs. They're good for close-ups but also as high-quality prime lenses with a fairly 'fast' maximum aperture, typically f/2.8, which is great for portraits or shooting in low light.
Which lens? Choose the best lens for your DSLR.
The only variations in this group are the Nikon 85mm f/3.5G AF-S DX ED VR Micro, which is two-thirds of a stop slower, at f/3.5, and the Tamron 60mm f/2 SP AF Di II Macro, which is one stop faster, at f/2.
A more crucial factor is what focal length is going to be most useful to you. Nikon cameras with APS-C-format sensors have a 1.5x focal length multiplier, or crop factor. The Nikon 40mm f/2.8G AF-S DX Micro would therefore have an effective focal length of 60mm, which is also useful for general shooting with a fairly standard effective focal length.
Lenses of 60mm equate to 90mm in terms of angle of view, so are good for portraits, whereas 105mm lenses give a telephoto reach equivalent to 157.5mm. You might think these could be good for action shots, but the focusing systems of macro lenses are often low-geared to enable the precise adjustments required for close-ups. That means autofocus can be too slow to keep pace with fast-moving action.
Focal length is an important factor to consider for macro photography. If you're shooting small bugs, for example, a greater focal length is preferable because the minimum focus distance will be longer. With a 105mm lens it will be about 35cm, but with a 40mm it's only about 16cm. This makes it hard to get close enough to tiny creatures without scaring them.
In fact, it's worse than it sounds because the focus distance is measured from the sensor, or 'focal plane', at the back of the camera. Take the depth of the camera body and the lens length into account, and the lens' front element can get very close to your subject. Shorter focal lengths are better for confined spaces and lower magnifications.
The quietness of the autofocus system can also play an important role when you're trying to photograph timid wildlife. All of the Nikon lenses on test, as well as the Sigma 105mm f/2.8 EX DG OS HSM Macro, feature very quiet, ring-type ultrasonic autofocus.
Best tripods and camera supports: 15 tested
This also has the advantage of full-time manual override in Single AF mode, so you can tweak the focus setting without switching back and forth between auto and manual focus options.
This is vital in macro photography because the depth of field is extremely small at the closest focus setting, which gives maximum magnification. At an aperture of f/5.6 it's just a millimetre or two, and even if you reduce the aperture to f/16, it will still only be 4mm.
Sometimes, in macro shooting it's easiest to just use manual focusing, to avoid the autofocus hunting through its entire range when making adjustments. The smoothness and precision of the lens' manual focus ring then becomes very important, though it's sometimes easier to make fine adjustments to the position of the camera instead.