Frequently Asked Questions About Macro Lenses

In recognition of B&H Photo Macro Week, this week's FAQ topic is—you guessed it—macro lenses.

What is a macro lens?

Macro lenses are generally defined as lenses that can photograph an object at life-size (1:1) or half life-size (1:2) magnification.

Are macro lenses available in different focal lengths?

Yes. For full-frame 35mm cameras, macro lenses that focus down to life-size or greater are available in focal lengths ranging from 15mm ultra-wide-angle lenses with 110° angles-of-view to 200mm telephotos.

If I own a 50mm macro lens that focuses down to life-size, why would I need a wide-angle or telephoto macro lens that also focuses down to life-size? What are the advantages?

The reasoning behind owning wide-angle, normal, and telephoto macro lenses is the same reasoning behind our decisions to purchase conventional wide-angle, normal, and telephoto lenses.

Wide-angle lenses take in a wider field of view, enabling you to photograph group portraits in tight quarters, sweeping photographs of interiors, landscapes, and dramatically dynamic close-ups. They also exaggerate special relationships within the frame lines, which can be used effectively if you have a sharp eye. Wide-angle macros can be used similarly, though in the case of life-size portraits of spiders, bees, and other creepy-crawlies, the end results can be frightening if not downright terrifying.

A key advantage of telephoto macro lenses is that they enable you to get in closer from a greater (and safer) distance to insects, birds, and other skittish animals compared to normal or wider-angle macro lenses. Longer focal length lenses also compress perspective and enable you to isolate your subject from the foreground and background more easily than with normal or wide-angle lenses.

And as any studio photographer will tell you, longer focal length lenses also enable you to get in closer to your subject with less chance of casting your own shadow or your studio lights within the field of view.

My lens has a close-focus mode. Does that make it a macro lens?

If your lens can focus down to half or full life-size magnification, it can be described as being a macro lens.

Aside from close-up focusing, are there any technical differences between "true" macro lenses and conventional lenses with close-focusing capabilities?

The key difference between a "true" macro lens and a conventional lens with close-up focusing capabilities has to do with the curvature characteristics of the lens's focus plane.

Most consumer lenses have slightly curved focus planes. While not an issue for most photographic applications, if you are reproducing important documents or 2D artwork, which require the corners of the frame to be as sharp and distortion-free as the center of the frame, you should be using a flat-field macro lens.

A conventional curved-field lens can deliver sharper corners once you stop the lens down 3-4 stops, but for critical detail, you'll get sharper edge-to-edge results when reproducing 2D artwork and documents using a true flat-field macro lens.

Can macro lenses also be used for taking "regular" pictures and photographs of distant subjects and landscapes?

Absolutely. Even though macro lenses are optimized for close-up photography, they can certainly be used as "regular" lenses with excellent results.

Technically speaking, flat-field macro lenses tend to be marginally sharper at their closest focusing distances compared to comparable conventional lenses focused at their respective closest focusing distances.

The reverse is equally true. When comparing photographs taken with similar focal length lenses—one a macro and the other a conventional lens—the conventional lens will often be slightly sharper than its macro counterpart when photographing distant subjects.

Are macro lenses recommended for portraiture?

Not only can macro lenses can be used for portraiture, some photographers prefer macro lenses specifically because they enable them to get in closer to their subjects compared to the more limited close-focusing abilities of conventional lenses.

If you choose to use macro lenses for portraiture, do be advised that, because true macro lenses have flatter focusing planes, the depth-of-field and depth-of-focus characteristics of the portraits captured with a macro lens may or may not appear narrower compared to portraits captured with comparable conventional portrait lenses, depending on the position, angle, aperture, and/or camera-to-subject distance. The differences are subtle, but a trained eye might pick up on the differences, which esthetically speaking are neither good nor bad.

Macro lenses also tend to be "clinically" sharper than conventional lenses at their closest focusing points, which, depending on your subject, might call for some degree of diffusion at the time of capture or post capture.

Are macro lenses the same as micro lenses?

Yes and no. The difference is that micro lenses can focus on objects at magnifications greater than life-size, that is, 2:1, 3:1, 5:1, 10:1, etc.

Among the few exceptions to this rule are earlier-generation Nikon AI and AI S-series manual focus Micro-NIKKOR lenses, which, despite the nomenclature, only focused down to half life-size (1:2). All current-generation Nikon Micro-NIKKOR lenses, while still not by definition micro lenses, do focus down to life-size (1:1).

If I do not have a macro lens, can I get the same or similar results using extension tubes or close-up lenses?

Extension tubes, reversal rings, and close-up lenses each enable you to get in closer to your subject in order to capture tighter close-ups with very good to excellent results.

For optimal results, I would recommend extension tubes and reversal rings because they do not rely on secondary optics to get you closer to your subject. If your lens is sharp, using it with extension tubes should result in sharp close-ups. The downside of extension tubes is that because they increase to distance between the rear element and the imaging sensor (or film plane), they increase your exposure time. If math isn't one of your strong points, fear not—your camera's built-in meter does the math automatically. All you have to do is hold still and press the shutter.

Reversal rings enable you to mount your lens onto your camera backward, which essentially turns the lens into a magnifying lens. If your lens has an aperture ring, you can manually adjust it to control exposure and depth of field, which is extremely narrow when you get in real close. If your lens does not have external aperture control, you can still use it, albeit at its widest aperture only.

Close-up lenses, which come in a choice of strengths and filter sizes, screw onto the front of your lens like a filter. Depending on the strength of the close-up lens and the focal length of the lens being used, it's possible to capture very good close-ups, macro, and micro photographs using close-up lenses. For added strength, close-up lenses can be stacked, though the optical quality decreases with each filter you add on. Close-up lenses do not affect exposure, but depending on the optical quality of the glass and the lens you are using it on, the quality of your results may or may not come close to the image quality of a comparable photograph taken with a macro lens.

Is there an FAQ topic you'd like us to tackle? If so, let us know in the Comments section, below.