Equipment and Techniques
"Macro" lenses specifically designed for close-up work, with a long barrel for close focusing, are one of the most common tools for macrophotography. (Nikon designates such lenses as "Micro" because of their original use in making microforms, but most lens makers use the term "Macro" or "Makro.") These lenses are optimized for high reproduction ratios. Most modern macro lenses can focus continuously to infinity as well, using complex focusing mechanisms that alter the optical formula. In most cases these lenses provide excellent optical quality when used for normal photography, although a macro lens may be optimized to provide its best performance at its highest magnification. True macro lenses, such as the Canon MP-E 65 mm f/2.8, can achieve higher magnification than life size, enabling photography of the structure of small insect eyes, snowflakes, and other minuscule objects. Others, such as the Infinity Photo-Optical's TS-160 can achieve magnifications from 0-18x on sensor, focusing from infinity down to 18mm from the object. However, macro lenses with 1:1 or 1:2 ratios are more common, and many of these find frequent use for general photography because of their excellent optics.
Macro lenses of different focal lengths find different uses: Continuously Variable Focal Length — suitable for virtually all macro subjects45–65 mm — product p hotography, small objects that can be approached closely without causing undesirable influence, and scenes requiring natural background perspective
90–105 mm — insects, flowers, and small objects from a comfortable distance 150–200 mm — insects and other small animals where additional working distance is required
Extending the distance between the lens and the film or sensor, by inserting either extension tubes or a continuously adjustable bellows, is another equipment option for macrophotography. The further the lens is from the film or sensor, the closer the focusing distance, the greater the magnification, and the darker the image given the same aperture. Tubes of various lengths can be stacked, decreasing lens-to-subject distance and increasing magnification. Bellows or tubes eliminate infinity focus. They can be used in conjunction with some other techniques (e.g., reversing the lens).