Auto focus — when is it appropriate? Cameras and lenses have undergone enormous changes in recent decades. With the advent of digital photography a cascade of new technology has become available to photographers at level, from casual snap shooter to full-time professional.
While many of these technologies are “game changers,” some offer advantages only in certain circumstance or to specific kinds of photography or photographers. Some are not well suited, but may be taken for granted as the “default” way of doing things. Specifically, is auto-focus always an advantage to all photographers?
Apart from autofocus, lenses have changed relatively little in the past 50 years or more compared with cameras. While modern lenses have improved coating, and zoom lenses are generally sharper throughout their range, lenses remain generally “low tech” components, compared to digital cameras.
Auto-focus has greatly increased the ease of focus for many kinds of photography such as sports, wildlife, street photography, and other kinds of “action” subjects, especially with long lenses, or where the subject is fast moving or cannot be easily tracked manually. Auto focus for these kinds of photography is indispensable.
Focusing is integral to composition Indeed, in many situations auto focus has much to offer, but is no substitute for finely honed skill both for engaging the photographer’s critical eye and for focus accuracy. This is especially true when deciding just where to place the precise point of focus in a composition. In such instances, auto focus may be more of a hindrance than a help in providing the immediate, accurate control that guides the photographer’s decision-making about focus point placement.
A responsive, manual focus lens brings elements of composition, focus, and camera / lens control together in ways that are often faster and more direct than with an auto focus lens. With a manual lens, you simply turn the focus ring until the image ‘works,’ rather than working around a focusing system that requires you either to focus / recompose using a central sensor, rely on fly-by-wire camera focus algorithm (e.g., closest focus priority), or reposition arbitrary focus points to align with the area of interest in the composition. Manual focus is the most direct means of composing and focusing simultaneously.
Auto focus requires both skill and knowledge of your camera, but is often an unnecessarily complex feature that deprives the photographer of immediate and subtle control over the critical area of composition-related focus. For many photographers, the tactile feedback provided by the lens’s focusing ring—hand and eye working together kinetically—is a key element in shaping fine, on-the-fly decision making about focus point and composition.
Do you need auto focus, really? Cameras have grown very sophisticated, but accessing the enormous capability and feature set of modern cameras has led to complicated, multi-level menus and awkward interfaces that even professionals struggle to use effectively. Coupled with an auto focus lens, the photographer may feel less in control of the camera than when camera and lens controls were simpler and more directly controlled by knobs, rings, and dials. Somehow, this directness made cameras pleasurable to use, a joy that may be obscured by the sheer range of features, capabilities, and options that current cameras and lenses offer. Focus is too important an element of photography to be less than directly controlled.
Connect with your photography Indeed, once you have worked with a top notch manual focus lens, you may feel, as many photographer do, that auto-focus is simply unnecessary for a good many photographic situations. You may also discover that your manual focus skill will improve to the point that even reliable focus on moving subjects is within your control — without having the camera and lens make the crucial split-second decisions. In the days before auto focus, photographers learned how to track moving subjects and maintain focus. Rediscovering such skills can revive some of the lost pleasures of working with a camera and lens.
Smaller, lighter, and simpler In addition, many manual focus lenses are often smaller, lighter, and more compact than their auto focus counterparts. Also, because Nikon has manufactured lenses for over 5 decades, there is an abundant variety of manual focus lenses available. Many of these produce first rate image quality on digital cameras. Since the camera equipment market has shifted to all-electronic, auto focus cameras, many superb lenses built to very high quality standards are available relatively inexpensively on the used market. These lenses, because they are all-mechanical, may be repaired and maintained indefinitely at lower cost than AF lenses. The lack of electronics means less to go wrong.
Experience precision optics and superior build-quality One of the experiences largely unknown to users of auto focus lenses is precise, accurate, and controllable manual focus. Indeed, auto focus lenses perform fast and usually accurate focus, but they are ill-suited for manual operation — even the best of them. One reason is that auto focus lenses have much shorter focus throw, by design, than manual focus lenses. Simply put, auto focus lenses have to get from minimum focus to infinity with as few increments of movement as possible.
Some AF Nikkors use a mechanical shaft drive system that requires a significant degree of “slop” in the focusing system in order to avoid straining the in-camera focusing motor, reduce friction, and speed up the transfer of focus from camera body to lens. The resulting lack of precision of this design (and Nikon is not alone here) can be easily when a lens is racked out to minimum focus: you can literally move the front section back / forth or up / down. This is even visible in many cases even through the camera viewfinder! Even the pro level AF lenses have a greater degree of lateral movement because of the necessary compromises involved with auto focus.
The pleasure of directness Almost all manual focus Nikkors have smooth, precise focus. Looking through the camera viewfinder and turning the focusing ring, puts you back in immediate control of focus selection. No need to use the selector on the back of your camera to reposition AF points; just turn the focusing ring until you see what you want!
The low-light advantage If you have ever tried working with a digital SLR and auto focus lens in low available light photography, you may have experienced the slow, cumbersome inefficiency and ‘hunting’ of auto focus. Focusing in low light is challenging for any focusing method, but an auto focus system — precisely because it cannot make judgments, zone focus, or predict where a subject or ideal composition will be at a particular moment and pre-focus — will struggle to find focus when lighting conditions are dim. Even worse if you own a consumer / prosumer level digital and happen to be photographing human subjects or wish to be inconspicuous, the focus assist light will activate, either annoying your subject or calling you out as ‘photographer.’ Contrast this with using a fast, manual focus prime lens that allows you to anticipate the action and quickly focus — or best guess — on the desired spot.
Built to last and renewable We at legacy2digital are Nikon camera and lens enthusiasts. We like to see legacy Nikkor lenses in use on modern cameras. We appreciate that a good number of these lenses have a useful life span of many decades. Unlike many AF lenses that have specialized components and circuitry, most manual Nikkor lenses may be repaired and CLA’d (cleaned, lubricated, and adjusted) by any competent camera repair person. With common-sense care these lenses can last indefinitely, and may be passed down through generations. The only maintenance required of them is regular cleaning of glass and CLA when needed (some Nikkor owners have used lenses 10, 15, even 20 years or more without a CLA).
Choices, choices, and more choices Nikon has produced an enormous number of different manual focus lenses over the years. For those new to photography or to the Nikon system, discovering legacy lenses is to stumble upon a treasure trove of possibilities. Many of the lenses that come standard on consumer and pro-sumer cameras, good as they may be, are often made for light duty use, have slow maximum apertures, and may be larger than desired. In contrast, a manual focus Nikkor with a fast maximum aperture can open up possibilities far beyond those of the standard kit zoom lens.