MACRO PHOTOGRAPHY
Up Close and Personal with Your Camera
Getting to the heart of the matter and examining the fine points of life has always been the forte of photography. There is no other art form out there that is as capable of examining the minutiae that surrounds us, with the same exactness, as when it is expressed through the camera. Perhaps that is why Close-Up and Macro Photography have become so very popular.
The term macro photography, macro lenses or macro lens setting has been abused and stretched from its true definition. In almost all sales literature, anything that can focus even remotely close has been referred to as macro. For the purposes of this article we do not want to get bogged down in technical terms and mathematical expressions. Therefore, we will make some broad definitions concerning photography, so that we will all understand what is being discussed. First off, general photography will be any picture taken from three feet, or farther (infinity), from the subject. Close-up photography will be any picture taken from three feet down to about six inches from the subject. Macro photography will be everything taken from six inches and closer and does not require the use of a microscope.
Figure 1 – Insect Macro
Accomplished nature and landscape photographers create close-up and macro images to reveal the beauty and order of the galaxy in even the smallest of scenes. Scientists use close-up methods to discover the important details of both flora and fauna. How may we, as eager enthusiasts, take advantage of the close-up motif? Certainly we may create pictures for those same reasons and also to infuse our work with variety, the spice of life. We may also need the technology to perform close-up copy work from old prints and documents for scrapbook purposes. There may be a future need to understand close-up work not yet imagined. Whatever your need, lets find out how to get up close and personal.
Interchangeable lens cameras will require some type of assistance to aid in the close-up pursuit. The standard close-up filter attachment is the least expensive accessory to do the job. Close-up filters usually come packaged in a set of three differing strengths to fit the front of a standard photographic lens. See them here. The close-up filter is convex shaped so that it increases the magnification of the lens to which it is attached, enabling it to focus closer. The characteristic that some find objectionable with the highly curved filter, is that it provides sharp focus only at the center and a gradual softening of the image towards the edges. This may be unacceptable in some applications and highly artistic in others. That is for the user to decide.
If the close-up filters are inadequate, the next solution may be either extension tubes or bellows attachments. Tubes are hollow rigid fixed length devices and bellows are hollow fully adjustable length flexible devices that fit between the camera body and lens. By increasing the distance from the body sensor (film plane) to the lens, close-up focus distances may be obtained. One advantage over the filter solution is that there is nothing added in front of the lens to detract from its quality.
A similar solution may be obtained by adding a teleconverter (tele-extender) between the body and to an appropriate lens. The teleconverter adds a similar amount of space, like the extension tubes, but also adds optical elements to increase the magnification power of the lens. Teleconverters do not operate with all lenses, therefore limiting their overall usefulness. They are generally matched to specific lenses of the telephoto variety. As with any item containing optical elements, price is a consideration; meaning, they cost more than tubes or bellows and you get the quality you pay for.
A true macro type of lens is the generally preferred choice of close-up / macro photographers using interchangeable lens cameras. The macro lens is specifically built for a particular job and they perform exceedingly well. A true macro lens has a double focus helix, meaning that the length of the lens grows to double that of a normal lens, thus providing its own extension capabilities. It may double in size internally by optical means or physically depending on its style or type. Macros are also of a flat field optical design. This means that the glass elements are physically flatter and have less curvature to them or the curvature has been compensated for in its optical formula. This makes a macro lens optically perfect for copy work, where any curvature or lens aberration would detract from the job at hand. Generally, macro lenses focus to a true half of life size (1:2) and with the use of an extension tube; 1:1 focus reproduction is accomplished. This means that if you photograph an object, such as a dime (17 mm diameter) you will create a 17 mm picture on the sensor at the image plane. The image will be exactly the same, full sized, as the original (1:1). Macro lenses are available in different focal lengths for different types of jobs.