Until 1996 I didn’t own an autofocus camera. Over the next few years, several compact 35mm cameras I had were autofocus models, but when I replaced my SLR, I chose a manual focus model. Why? I was used to using split-image and Fresnel screen rangefinders, and ground glass suited my close-up photography. I didn’t need autofocus! But as my eyes and I grew older, autofocus seemed increasingly appealing, and eventually I decided my eyesight was just not reliable enough any more.
Today, all of my systems are autofocus, and they are getting better every year (or are my eyes failing more each year?). But oddly, there are many situations where autofocus is not as good as manual, even with my 63 year old eyes!
Given how many different focusing modes modern cameras offer, this might surprise some people. Perhaps you are one of those photographers who never uses their camera's manual focus ability; maybe you didn’t even realise that manual was an option, even if you had experimented with settings like Single-Shot, AI and AI Servo(which I will save for another Intel).
Horses for Courses - How could human judgement be better than precision, computer assisted automatic focus? Obviously, it is good enough to provide adequate focus; until 1977 there were no autofocus 35mm cameras; the first 35mm SLR with autofocus didn’t come along until 1981, and that had the motor in the lens. Autofocus moved from the lens to become integrated into the camera in 1985. Just a couple of decades, yet photographers have been making well focussed photographs since the first decades of the 19th century. Clearly, manual and automated focus both work. And sometimes manual works better. Even with old eyes!
There are several areas of photography where you should at least experiment with manual focus: close-up photography; low-level light; some portraiture; when a controlled out-of-focus effect is desired; shooting through glass; in “messy” or complicated places; when photographing fast moving subjects.
Manual will not always outperform autofocus in these situations, but sometimes it will be the only way to get the shot. For instance, when using using teleconverters and other accessories you may lose your autofocus and have to use manual. Manual is always better if you want to know the effect of your focus: an old-fashioned ground glass focussing screen let you see just what was in and out of focus and required you to make judgements about the composition as you altered the focus point. Autofocus has trained us to listen and press the shutter release when we hear a “beep”. that is not necessarily the best way to judge composition!
Getting Close-up - In macro, table-top and other close-up photography, depth of field can be very shallow. Autofocus doesn’t mind; it works just fine except for one thing: it doesn’t know what should be in focus.
The camera will focus on whatever it can, and it may not be what you expected. You need to be really specific about where you focus, and often the best way to do that is to engage manual focus, set the lens to its minimum focus distance and move the whole camera in and out until you get exactly the effect you want. Macro photographers may even opt for rails that attach to a tripod to perform just that operation of rolling the camera in and out in tiny increments. If you want to attach you camera to a microscope, manual focus is the only option too.
When the Lights are Low - Romantic? No, just frustrating, as the lens hunts for focus. Dimly lit environments are difficult for most cameras and lenses when it comes to focusing. Even if it manages, you can wait so long for the lens to zoom in and out from one end of its focussing range to the other trying to grab something, that you miss miss shot after shot. Snapshots? Candids? Peak of the action? Forget it...unless you can switch to manual! Then you can find your focus point and get the shot you wanted.
Portraits and People Pics - It is almost a rule that photographs of people should have eyes in perfect focus. Autofocus can do it reasonably well, but only manual focus gives you complete control without constantly worrying about lining up different focusing points, invoking focus lock and reframing before exposing. Manual focusing helps to ensure the viewer is drawn to the part of the face that you want them to notice.
Intentional Out of Focus - It’s pretty obvious that autofocus won’t give you this effect! How about a softly diffused image of a rose through frosted glass? Yes, your camera could focus on the glass and show every detail of that, including the rose’s form; might be a great shot, but it isn’t the one I want; I don’t want to see the glass at all, so... Manual Focus! When you want the play of light and dark or colour and form rather than a concrete image, MF will give you images that autofocus can’t.
Reflections and Fencing - Windows are rarely invisible, and even though you can see through a fence, left to their own devices, cameras want to photograph the reflection in the glass or the fence itself rather than what you are looking at through them.
Taking pictures out of a train window, of a shop display or a piece in a display case, or trying to photograph animals at the zoo is tricky for autofocus. You could set the camera on Landscape Mode (usually symbolised by a mountain icon); that locks focus on infinity and keeps the wire or reflections out of focus which might be OK on the train or aeroplane, but it will not give the accuracy you want for those little birds or the hyena just inside the cage.
Manual focusing lets you put things right - focusing on the subject instead of the glass, the reflections or the rails.
Messy Places - One little bird flitting around in the branches of a shrub defeats autofocus every time! The longer the lens and the dimmer the lighting, the worse it gets. Manual gives you a fighting chance, and manual focus plus prefocus on the spot the subject returns to most often, or at a similar distance boosts your chances immeasurably!
Fast Motion - Action or rapid change is hard for autofocus - not impossible, but chancy. It is hard to pan with a subject in autofocus; by the time it locks on, the picture is gone. It works better if the subject is coming straight towards/away from you, especially in AI (continuous focussing mode), but only if there is plenty of light.
You’ll find that manual focus gives better results, particularly if you shoot in continuous shooting/burst mode. One way to increase you hit rate is to prefocus on a point that the subject will move through, and starrt shooting a moment before they reach that point.
Diving, boxing, jumping and other action subjects where the action is sudden and brief is also tricky but possible. It is often better to go for manual focus, and with the camera prefocussed on the area where the action is likely to happen, turn on burst mode and try to predict the critical moment - shoot what seems a bit too soon: reflexes and shutter lag are going to plague you otherwise.
Light-Hungry Accessories - Your longest lens is always just too short; your finest macro takes you almost close enough. So you buy a teleconverter or a set of extension rings, or a bellows, or a reverse-mounting ring. Some disable your autofocus system instantly; others work, but only until you stop down below f4. If you want to use these very handy gadgets, you will have to come to grips with manual focus. But not to worry; it is actually rather satisfying, and not hard.
SLRs have a simple switch, usually on the lens, to shift from auto to manual focus. Even when manual focus is engaged, the auditory and viewfinder “focus confirmation” signals still work. Compact digital compacts that allow you to autofocus may operate with a switch like the SLRs or you may have to set manual focus in a menu. In either case, they often have a setting that magnifies the central portion of the image as you focus to improve accuracy: very handy.
If you are in the market for a camera, check out how easy it is to use the manual focus settings: you are going to use them!
