The world of close-up photography is diverse and provides two main options: document the subject as it appears to the eye or get creative and use selective focus. To depict the subject in its realistic state, stop the lens down to one of its smallest apertures to cover the very limited amount of depth of field. This requires a lot of light and often a tripod to prevent camera shake from long exposures. A flash is often a good solution to the problem. If the subject moves due to the wind or motion, a flash is required if you want to stop the action. Conversely, the selective focus technique allows you to handhold the camera in most situations where the lens is set to its widest aperture, which allows a fast shutter. Corresponding shutter speeds that go hand in hand with wide-open apertures are often fast enough to get a sharp image.
Selective focus provides very shallow depth of field. In a three-dimensional subject, this means that the only point of true sharpness will be the exact plane on which the lens is focused. For instance, in the accompanying close-up shot of the daylily, just a few of the anthers are sharp. While separated by only millimeters, those in front and behind the plane of focus fell out of the depth of field. Note that the back of the flower is totally out of focus. Had I wanted to record more depth of field to show all parts in focus, I would have stopped the lens down to ƒ22. The corresponding shutter speed would have necessitated I use a tripod and the wind be absolutely still.
If the subject lacks depth, as in the case of a postage stamp or other single-planed subject, as long as the lens remains completely perpendicular to it, depth of field isn’t as critical. While this is a plus in some cases, it prevents the photographer from creating a selective focus image.
Means by which a photographer can get up close and personal with their subjects are through the use of extension tubes, teleconverters, close-up diopters or true macro lenses. All have their pluses and minuses regarding ease of use, cost, final outcome, size and diversity while in the field. A bit of research regarding each of these methods will net you the most bang for your buck.