A Macro Photography Primer
Getting Up Close And Personal For Some Great Photo Ops

A Macro Photography Primer

Diana Butterfly
Photos © 2002, Kenneth J. Stein, Ph.D., All Rights Reserved

In photography courses that I have taught, it has been common for people to tell me about their "Macro" function on their 35-70mm or 70-210mm lens. Although these lenses are adequate for some close-up work, they do not have the same close focusing ability as dedicated macro lenses, and do not perform as well. Another favorite of some folks is the close-up lens, a type of screw-on magnifier that is placed in front of a lens. These lenses have the capability to provide a variety of magnified images, although these images will not be as tack-sharp as those provided by macro lenses. If you are serious about macro photography, then by all means consider purchasing a dedicated macro lens.

What are macro lenses, and how do these differ from micro lenses? For some folks, especially Nikon users, macro and micro refer to the same thing--"close-up photography"--or making small objects appear large in a photo. Although the terms macro and micro photography are used synonymously, macro photography generally refers to most close-up work conducted with macro lenses. By contrast, micro photography refers to high magnification close-up work that goes beyond the use of macro lenses.

Yellow Fringed Orchid

Reproduction Ratios
Macro lenses are characterized by their magnification rates, or more commonly, their reproduction ratios. These ratios represent the relationship between the actual size of the subject and its virtual size, which will eventually appear on the negative or slide transparency. Reproduction ratios are always stamped on the adjustment barrel of the lens, usually above the distance scales; e.g., for any given distance to subject, there corresponds a reproduction ratio. A glance at these scales makes it possible to determine the image size that will eventually appear on the film.

For example, when I am shooting a subject at a distance of 2 ft using my Canon 50mm macro, the image that appears on the film will be 1/10 its actual size. On the other end of the scale at 9" from the subject (minimum focusing distance), the image that will appear on film will be 1/2 its actual size. These distance scales and reproduction ratios vary among macro lenses of different focal lengths. These criteria convey a sense of working distance to macro photographers; e.g., the longer the focal length, the greater the working distance.

Common Sulfur

Working Distance
Working distance is the minimum distance between the front of the lens and the subject. For example, if I am shooting a mushroom using the 50mm macro lens, I might take the 1/2 life-size picture at a working distance of 4" from the subject. To obtain the same size (1/2) image using the 105mm macro lens, I could shoot the mushroom a little more comfortably at a working distance of about 9.5". It should be mentioned that the working distances used in these examples differ slightly from the focal distances that are stamped on the lens barrel. This is because the focal distance is a physical parameter of the lens. It represents the actual distance from the subject to the film plane at the back of your camera.

What if you are shooting larger, more active subjects, whether they are butterflies or poisonous snakes? Clearly, these subjects will not have the same sense of comfortable working distance as you do. For these kinds of subjects you might consider purchasing a 180mm or 200mm macro. Not only will you have a better working distance, but you can obtain very good reproduction ratios at distances of 2-4 ft.

I prefer a 50mm macro for over 90 percent of my macro work, even though I own 105mm and 180mm macro lenses. Although the 50mm has been largely described as unconventional for outdoor work, I find that I think clearer with it. When I am face to face with, or on top of, my subject, it is not only the same as being there; I am there, and feel that I am part of the composition!

I have always felt that the working distances afforded by the longer focal length macros makes me feel "too comfortable" during shooting. What is wrong with comfort? Although it is a personal point of view, if I am comfortable, then the challenge for the shot seems to be lacking. Taking quality pictures is no different from writing, painting, drawing, or doing anything worthwhile. I feel that if I am not under a little bit of pressure, I will not get my best shots.

Red Cup Fungus

Depth Of Field
Macro lenses do have their physical limitations. Chief among these is depth of field, which drops off rapidly as you approach magnification rates of 1/2 life size, or greater. For example, when I am shooting 1/2 life size at f/16 with my 50mm macro, I know that I have only 1/4"of depth to play with; the subject can easily become out of focus. When it comes to composition, I had better do what I can to make the subject a planar surface, or, select that part of the subject that needs to be in focus.

Keep in mind that the depth of field at close distances drops off more rapidly when working with longer lenses than with the shorter focal length lenses. Yet, it goes without saying that telephoto lenses provide a comfortable working distance.

Rue Anemone

Macro Accessories
What other equipment do you need for macro photography? You will probably need a tripod. When you shop for one make sure that it has the features to accommodate the kinds of macro photography that you will be doing. If you are interested in roadside wildflower photography, your needs will be much different than someone spending time hiking around in the swamps, in the snow, and in the mud. Make sure that it is very sturdy and that it can support your entire lens collection. Most minipods are extremely useful for some close-ups, especially those subjects that are only several inches high. However, like many of the lightweight tripods, the minipods can only be used with the shorter focal length, lightweight lenses.

As you gain macro photography experience, you may find that your present equipment limits your shooting capabilities, especially the ability to increase your reproduction ratios. There are several remedies available. Aside from close-up lenses, which I mentioned earlier, there are also extension tubes. These are tubes of fixed length (e.g., 25mm, 50mm, 100mm) that are placed between the lens and the camera. These tubes function by physically extending the lens, thereby increasing its magnification capabilities. They certainly allow you to become closer to your subject, but at the cost of light reduction (one or more f/stops) and a corresponding decrease in depth of field. Although extension tubes greatly magnify an image, they can be cumbersome to work with. A slight movement of your tripod, or a slight movement of your subject, is enough to immediately put your subject out of focus.

These situations, especially those where magnification is greater than 1x, call for focusing rails. These are mechanical devices that insert between the base of the camera and the tripod head. Their primary function is to allow fine focusing for a given magnification. Once you have decided that you want a magnified image (e.g., 2x), use the focusing barrel on your lens to select that magnification. Then, use the focusing rail to bring your entire camera slightly closer to, or farther from, the subject.

Indian Paintbrush

Framing And Composition
Most people starting off in macro work place their subject in the dead center (this sounds just like regular photography, hmm?). Sometimes this can work to your advantage; however, most of the time you need to pay special attention to composition, especially the subject's posture, lighting, shadows, and objects for contrast. When you find a subject, say a flower, try to find the best one possible. Look at its posture. Is it the best representative of the species? Can this flower stand on its own? That is, can you isolate it from competing subjects? On the other hand, look for competing subjects in the foreground or background that make for a better picture. Pay as much attention to your background as you do the subject.

Know Your Subject
You might do well to know a little bit about the biology and behavior of your subjects before embarking on macro photography. As a professional entomologist, I know firsthand that insects are a lot like people--each has its own behavior and comfort zone. They will let you get close, and of course, let you know when you are getting too close. A seasoned beekeeper knows the behavior and temperament of the bees within each of his hives. Some are docile and slow reacting; others are quite aggressive and can become easily irritated. However, most have a working distance that can only be learned by spending time with them and observing their behavior.

Butterflies also have their comfort zone and most become skittish when you get closer than a couple of feet from them. However, some species will allow you to get close enough to almost touch them. Others are much more defensive and will begin to take flight when you are seemingly far away.

Photographing insects does not translate into photographing other animals. Although the photographic principles are the same, the technique is not. I recall taking a picture of a Spitting Cobra in the Eastern Sahara Desert, in Egypt, and then having a colleague get between the snake and me to divert it with a stick, while I rolled away from it. Even though I knew a little about the behavior of cobras, I learned a valuable lesson--cobras are not hornets or butterflies! Not only is it important to intuitively size up your subjects as you approach them, it is important to have the right working distance, which is provided by using the correct lens.

Start To Explore
Macro photography is truly a world in itself. When I view my slides with a 10x loupe on a light tray, I am always amazed at what I find--and learn! Many of the images possess details and features that would not have been apparent to a passing observer. Indeed, some of these weren't visible to me when I captured them on film. As a biologist, I find that macro photography is a lot like life--being at the right place at the right time--timing is everything! Catching the rare, unblemished butterfly when its posture is perfect and it holds the fleeting, perfect pose for the camera is a great reward. Capturing a golden sliver of sunlight glancing across the petals of a flower, knowing that it will be gone in seconds can result in great photos. And finding a hornet in an "I'm guarding my nest to death" mode can't be beat. Nothing can top a good still close-up image--it is a large slice of life!