Macro lenses: buying guide

If you're serious about capturing the world up close sooner or later you'll feel restricted by your normal lenses and start to think about investing in a dedicated macro lens. This investment will see you discover a whole new miniture world and you'll be glad you took the plunge. Here we provide you will the key features to look for in a macro lens.

About macro lenses

Normal lenses are optimised so that sharpness and contrast get better towards infinity focusing, macro lenses are the opposite – providing brilliant sharpness, contrast and high general image quality up close. Macro lenses are generally bitingly sharp bits of glass, which is why many pro photographers use them as portrait lenses (although sometimes they can be too sharp for this!). As well as the ability to capture truly stunning close-ups, they’re capable of shooting anything else you come across.

Magnification ratio
The magnification ratio, or reproduction ratio as it’s also known, is a crucial feature. True macro lenses offer a magnification ratio of 1:1, meaning your subject will be the same size as the image sensor it was taken on. 1:2 means the subject will be double the height and width and so on. If magnification is less then 1:1, it’s unlikely to be a true macro lens.

Focusing mechanisms
All modern macro lenses have an autofocus facility, but if you’re buying second hand you could consider a manual focus only lens – not a problem for macro, but inconvenient if you want to use it more generally too. Autofocus lenses will either have ‘silent’ motors or older screw-driven ones - you’ll pay more for a silent lens, but it maybe worth it if you’re concerned about noise scaring subjects.

It’s also worth noting whether the lens focuses internally – if it does it won’t extend in length as you change focus, but a variable-focus lens will. This isargely down to personal preference and if you have a sturdy tripod any change in centre of gravity caused by lens movement should be combated anyway.

Vibration Reduction
Is Vibration Reduction important on a macro lens? If you’re planning to use a tripod at all times then no. If you may do some spur of the moment handheld work or are planning to use it generally then you’ll probably want a VR lens.

Focal length
Macro lenses come in various focal lengths, but the most common lenses tend to be 50mm, 60mm, 100mm, 105mm and 180mm. What difference does this make? Lots. Firstly, the shorter the focal length, the lower the cost – that rule of thumb applies across all brands, although a fast aperture will push the price up. As well as being cheaper, however, the lower the focal length, the smaller and lighter the lens will be.

For example the Sigma 50mm f/2.8 EX DG macro lens has an SRP of £319.99 and weighs 320g, while their 105mm f/2.8 EX DG macro lens has an SRP of £499.99 and weighs 460g. So, is a lower focal length better? For your wallet and back yes, but not always for your photography. The most important factor to consider, in terms of photography itself, is that the lower the focal length, the closer you need to get to your subject. If you know you’ll only be shooting static subjects, then it’s not such a big deal but anyone who’s eager to shoot insects and other small creatures should consider spending a little more and going for a 100mm or 105mm lens. It’s seriously frustrating when you’re continuously scaring potential subjects away because you have to get so close…

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