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Close-Up Lens Considerations

Most lens manufacturers offer 50 mm or so close-up lenses, ~100 mm close-up lenses, and ~180 close-up lenses. Photographers who are new to this specialized field may not know how or why to choose among them. Life-size is life size, right?
Yes, life size is life size, but there are still significant differences between close-up lenses.
The most readily apparent differences between these three categories are cost, size, and weight. The 50-60 mm close-up lenses are smaller, lighter, and less expensive than the 85-105 mm ones, which are, again, smaller, lighter, and less expensive than the 150-200 mm ones. These differences can be nearly two pounds, and well over a thousand dollars. Cost and easy carrying can be overriding criteria for some, and smaller macro lenses can be perfectly sufficient.
If size, weight, and cost were the whole story, then everyone would be using the shortest close-up lenses they can. So, longer focal length close-up lenses obviously have some pretty compelling advantages, too.
One advantage is that longer focal length lenses have a narrower angle of view than shorter focal length lenses. While a honey bee photographed at life size will be the same size on film (or sensor) whether snapped with a 50 mm lens or a 180 mm lens, the 50 mm lens will show a much wider sweep of the bee's background than 180 mm lens will. The longer lens's narrower angle of view "isolates" the subject more than the shorter lens's broader angle of view. Since photographers don't like to include extraneous details in their compositions, they often prefer longer close-up lenses for their facility at singling the main subject out from any distractions in the background.
Another point that sometimes favors longer close-up lenses is greater working distance. A 50 mm close-up lens will need to be about 9.5 inches from the subject in order to shoot the subject at life size, a 100 mm will need about a foot, while a 180 mm close-up lens will need to be about 19.5 inches away from the subject in order to shoot it at life-size. It is much easier to avoid scaring away (or enraging) small creatures from 19.5 inches than from 9.5 inches, making it preferable to photograph skittish or cantankerous small animals with longer focal length close-up lenses. (On the other hand, if you are trying to photograph a waist-high wildflower from the top down, a 50 mm or 100 mm close-up lens will be preferable, since you can only shoot from so high, without needing a step-ladder to stand on. Which focal length close-up lens will serve you best depends on the subject and angle.)
Besides the issue of alarming small creatures, greater working distance also makes lighting easier to deal with. A 1:1 shot with a short close-up lens could require you to get so close that your camera gear (or your body) blocks the natural light from your subject. The greater distance with longer close-up lenses prevents this. Similarly, this greater working distance allows you to easily use a regular flash with longer close-up lenses. A normal flash head can be difficult to use with the short working distance of smaller close-up lenses, which may make a special close-up ring flash (which attaches around the front of your lens) necessary.
A final advantage of the longest close-up lenses is that they come fitted with lens collars. A lens collar is a ring shaped clamp around your lens, with a "foot" jutting from the bottom. The clamp is for holding onto the lens, and the foot attaches to the tripod. By shifting the area where the tripod couples with the camera system from the bottom of the camera body to the foot of the lens collar, the camera system can be supported from a more neutrally balanced point. This minimizes camera-system movement from instability. It also lessens stress upon the lens mount (the area of the camera body where it locks to the lens).
Lens collars also have a couple other significant advantages for close-up photographers, beyond shifting system support forward of the camera body. The first is that the lens collar's ability to be loosened allows for rotating the camera from horizontal to vertical (or back, or anywhere in between) in a quick, easy manner, while the distance, angle, and center of the picture are maintained. Other methods of shifting between vertical and horizontal require dismounting the camera, and/or adjusting the tripod, and then recomposing from scratch--which is a more involved and more time-consuming process.
The second other advantage of lens collars is that (when the lens collar's foot has a quick-release plate attached, and the tripod's head has a quick-release clamp attached) they allow easily moving the camera and lens forward in minute increments while maintaining the same composition, without needing to move the tripod forward, readjust the tripod and the tripod head, and recompose. A lens collar's increased facility with isolated forward/backward adjustments, and with isolated vertical/horizontal rotation adjustments, is especially helpful with extreme close-up photography, where the set-up often needs to be exacting to within millimeters in multiple dimensions in order for the composition to work.
So far, optical quality considerations haven't been discussed. Usually, these considerations ("Which is sharpest?", etc.) are foremost in photographers minds when making lens decisions. While there are minor differences (the longest close-up lenses tend to be best, the shortest tend to be second best, and the middle lengths tend to be third), choosing a close-up lens is a rare case where optical considerations are best kept secondary to other factors. Close-up lenses tend to be optically superb, and among the most highly corrected (for field curvature, barrel or pincushion distortion, and chromatic aberration) kinds of lenses, regardless of focal length or manufacturer. Angle of view, working distance. and lens collar, are generally more germane.
A final factor to consider when choosing a close-up lens is how else you will be using the lens. These lenses can be used for more than just close-up work; they make great lenses for subjects at greater distances, too. Many professionals and serious amateurs get dedicated close-up lenses, and do not factor other uses into their close-up lens choice, but most cannot afford that luxury. Double use becomes an important point. So which are best for more general photography? That is entirely dependent upon the subjects you like to shoot, your style, and personal taste. Generally speaking, more people find the middle focal length close-up lenses better for general use than the shorter ones or the longer ones. |
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