Manual focus When is it needed? How to use it?

All modern cameras have auto focus features. So why do photographers still often use manual focus? In what circumstances it is used and how to work with it - read in our lesson!

When may manual focus be needed?

Difficult cases for auto focus. Despite the fact that autofocus systems are improving every year, they still sometimes experience difficulties. Surely you are faced with a situation where automation doesn’t want to focus in a certain place. Instead, she begins to “scour”, focusing the lens back and forth, but without getting into the target. Let's analyze the main cases that are difficult for autofocus.
  • Focusing on low contrast, translucent objects . Try focusing on the smooth white ceiling or taking a picture of the surface of the window pane. Autofocus in such cases may well save.
  • Autofocus may not cope when the subject is blocked by foreground objects . The simplest example is shooting an animal in a zoo through a grate: autofocus may very well begin to “cling” to the grate. Instead of torturing the autofocus system, in such conditions it is quite possible to switch to manual focus.
Nikon D600 / Nikon 85mm f / 1.4D AF Nikkor Between me and the model is a translucent glass (it gives glare). When shooting, autofocus periodically “clung” not to the face, but to cracks in the glass.
  • Shooting in strong backlight. For example, when shooting against a bright sunset or dawn sun, you will encounter the fact that autofocus will work worse than usual.
  • Night shooting. If the conditions of a city night, autofocus, in general, can do it, then when shooting landscapes with a starry sky, the only thing left to do outside the city is to manually aim. Auto focus here is not your assistant.
Nikon D810 / Nikon AF-S 18-35mm f / 3.5-4.5G ED Nikkor Shooting the starry sky. If in previous cases autofocus can still be defeated and made to focus where it is needed, then in conditions of pitch darkness, you will definitely have to manually adjust the sharpness.
Use of autofocus optics. There are many lenses that do not support the auto focus function. Among them are old obsolete lenses and completely modern optics. Many photographers are interested in ancient optics, as it gives a peculiar, “vintage” picture. Fortunately, there are a lot of lenses that can be installed on modern digital SLRs (including through adapters).
Nikon MF 50mm f / 1.2 Nikkor - ultra-fast manual focus lens
PC-E NIKKOR 85mm f / 2.8D. Tilt-Shift lenses also do not have autofocus
Nikon D80 The frame was taken with an old portrait lens with manual focus. Such lenses are usually used to indulge in bokeh - an interesting blur in the blur zone.
Landscape photography. When shooting landscapes, it often happens that the foreground (which is usually focused on) is located on the periphery of the frame, where there is not a single focus point. One option for focusing in this area is to use manual focus. Also, advanced photographers often use hyperfocal focusing when shooting landscapes . This requires focusing the lens at a certain distance, and this is easier to do manually using the scale of focusing distances on the lens, rather than using autofocus.
Nikon D810 / Nikon AF-S 18-35mm f / 3.5-4.5G ED Nikkor
Macro shot. In macro photography, autofocus is very difficult. So it turns out, firstly, due to the fact that the depth of field for macro photography is extremely small. The slightest change in the distance between the camera and the subject (even a few millimeters) will lead to loss of focus. Secondly, the closer the captured object is to the lens, the more the lens lenses have to move to focus, and this greatly slows down the operation of autofocus. Therefore, photographers prefer to focus manually when shooting macro, fully controlling the entire process and thereby eliminating possible automation errors. At the same time, macro photography is characterized by a special way of focusing: not by rotating the focus ring, but by moving the camera itself a little closer or a little further from the subject. But more about that below.
Nikon D600 / Nikon AF-S 50mm f / 1.4G Nikkor (with macro rings) The smaller the subject, the shorter the required shooting distance. The shorter the shooting distance, the smaller the depth of field and the more difficult it is for autofocus to work.

How to enable manual focus?

On entry-level cameras (for example, Nikon D3300, Nikon D5500), everything is simple: to do this, turn the AF / M (Auto Focus / Manual) switch on the lens to M.
On entry-level models (e.g. Nikon D3300 and Nikon D5500), the A / M switch must be set to M (Manual). Autofocus is now disabled. Focusing will be done by rotating the focus ring on the lens (highlighted in blue).
Advanced cameras (starting with the Nikon D7200) have two autofocus switches: both on the lens and on the camera. How to use them correctly? If an AF-S lens equipped with an ultrasonic focusing drive (most Nikon lenses are equipped with a lens) is mounted on the camera, it will be enough to put only the switch on the lens itself in the “M” position. Please note that if you turn off autofocus with the lever on the camera, and leave the switch in the “A” position on the lens, you can disrupt the auto focus drive, the lens will have to be repaired. An exception is made for lenses with autofocus mode with manual adjustment - in this case, the AF and manual focus switch on the lens will look like M / A-M. More on this mode will be described below. If you use an AF lens (and not an AF-S), switching the lever on the camera is mandatory: after all, such lenses are physically coupled to the camera with a “screwdriver” focusing drive. And to disable this drive, you need to turn this lever. To summarize: when using AF-S lenses, it is better to use the switch on the lens. And when using "screwdriver" AF lenses, you must first switch the lever on the camera.
On advanced cameras, AF on / off switches are on the lens as well as on the camera. When using AF-S lenses, it is better to use the lever on the lens (highlighted in blue), and when using “screwdriver” AF lenses, you must first switch the lever on the camera (highlighted in yellow).
How do you know which autofocus drive your lens is equipped with - AF-S or AF? To do this, just look at its full name.
A lens equipped with an AF-S drive : Nikon AF-S 50mm f / 1.8G Nikkor When working with AF-S lenses, to enable manual focusing, just turn the switch on the lens itself to the desired position.
Lens equipped with AF screwdriver: Nikon 50mm f / 1.8D AF Nikkor. When using such lenses, you must use the switch on the camera.
Now the camera will focus only manually - for this you need to twist the focus ring on the lens. Please note that the focus ring on different lens models may be in different places on the lens barrel: a little closer to the camera or a little further. In addition, the focus ring should not be confused with the zoom ring of the lens (with it we “zoom in, zoom out” the picture.)

Manual Focus Methods

So, we know when manual focusing may be required. Now let's figure out what manual focusing methods are.

Focus on a specific distance

Perhaps the easiest focusing method, especially if your lens is equipped with a focus distance scale. Just set the desired distance on this scale, and you're done - the sharpness will be at the selected distance. This method is well suited for landscape photography when you need to visit at hyperfocal distance or at infinity. On this, the scope of this method, perhaps, ends. Focusing on “infinity” is simple: you need it when the objects are very far from us.
Nikon 17-55mm f / 2.8G ED-IF AF-S DX Zoom-Nikkor focus distance scale. At the moment, the lens is focused on “infinity”, this can be seen from the jackal of focusing distances, on which the “?” sign is visible, combined with the risk of the scale.
At what distance does the “infinity” for the lens begin? It all depends on the focal length of the lens. The larger the focal length, the farther away is “infinity”. Usually we are talking about tens of meters. In the case of wide-angle optics, we can talk about a few meters. But what if the subject is close to us, but at the same time, I want to make the whole frame sharp without blurring the background? Here the hyperfocal distance comes to the rescue. Hyperfocal distance is a distance when focused on which everything from ½ of this distance to infinity will fall into the depth of field. The hyperfocal distance will depend on the focal length of the lens and the aperture value at which you are shooting. How to calculate hyperfocal distance? There is a special formula for this, which can be found in our special article on advanced work with depth of field. But it’s easier to use special calculator programs for this. They are available on the Internet, and special applications for smartphones have been released. Here is some of them:
HyperFocal Pro
F-stop calculator
DoF calculation for WindowsPhone
It makes sense to use hyperfocal distance in landscape photography, when working with wide-angle optics, where it will give a significant gain in the depth of field, and will allow it to be used as rationally as possible. Focusing on a distance will not allow you to focus very accurately, only approximately. So, this method is not suitable for shooting portraits and reporting on the open aperture.
Nikon D810 / Nikon AF-S 18-35mm f / 3.5-4.5G ED Nikkor Hyperfocal Focused Landscape

Focus by changing the shooting distance

This method is often used when shooting close-ups. Each lens has a minimum focusing distance. Why not choose her? Now that the lens is set to the minimum shooting distance, just bring the device to the subject to the desired distance. Holding the device in our hands, we can move it a little back or forward to catch the focus in the frame.

Focusing with the viewfinder and camera rangefinder

Modern Nikon SLR cameras are equipped with a special mechanism that can tell the photographer what is currently in focus and where to turn the focus ring to sharpen what is in focus. Let's see how it works. You can see the legend shown below in the viewfinder of the unit (in the lower left corner). They appear during auto focus, but with manual focusing of the lens, they will be most useful. Symbols for the focusing process in the viewfinder:
Focus done
The lens is focused closer than necessary.
The lens is focused further than necessary.
Automation cannot determine the accuracy of focusing. This happens in low light or when trying to aim at a very uniform, low-contrast object (for example, a white ceiling). In this case, try to combine the focus point in the viewfinder with some contrasting object in your future frame.
To focus in this way, first you need to select the desired focus point in the viewfinder of the device. It is on it that the range finder will work. Now, focusing on the arrows "left" and "right", turn the focus ring in the corresponding direction until the circle lights up in the viewfinder. Done: you are focused! The younger Nikon DSLRs (Nikon D3300, Nikon D5500) use a simplified scheme of the rangefinder. There are no arrows "right" and "left", but there is only a circle confirming the focus. To manually focus on these cameras, simply twist the lens ring until the same circle lights up in the viewfinder. This focusing method is very accurate. Therefore, it is suitable for working on open diaphragms. With it, it’s convenient to shoot portraits with “manual” optics.

Live View Focus

A very interesting, fast and accurate way to focus manually is the Live View mode. With manual focus through Live View, the photographer can enlarge the desired area of ??the image, and you can perfectly focus on the sharpness in this enlarged fragment. In my opinion, this method provides the most accurate focus. In addition, we can control the sharpness of the frame before shooting, while the situation with the sharpness in the viewfinder is not so noticeable: you have to strain your eyes to understand what is sharp and what is not in the frame.
Nikon D3300 Camera In the yellow frame - the button for enabling the Live View mode, in the blue - the button for enlarging the image.
So, turn on the Live View screen, select the frame area that we will increase, and click on the button with the magnifying glass (just like we do it when viewing the captured images). After that, it remains only to twist the lens focus ring, focusing on the screen of the device. I often use this method in the most difficult situations, including when shooting a portrait with high-speed portrait lenses. With such surveys, the depth of field can be a matter of millimeters, which means focusing should be perfectly accurate. Since the portrait focuses on the eyes, I use Live View to enlarge the area of ??the frame with the eyes of the model and focus.

Autofocus with manual adjustment. M / A mode

Some Nikon lenses can work in a very interesting mode, combining automatic and manual focus. On some lenses, instead of the usual switch between manual and automatic autofocus, you can find the M / AM switch.
Lens with conventional AM switch
The M / AM switch indicates that we have a lens that supports autofocus with manual adjustment.
In this mode, while holding the shutter button half-pressed, you can take control of the focus on yourself at any time. As soon as you turn the focus ring, the autofocus will turn off, yielding focusing to you. This is convenient when you want to manually adjust the focus a bit before shooting. Suppose the camera cannot focus, and the lens “scours” back and forth in search of sharpness. At this point, you can immediately take control of yourself by focusing the lens where necessary, and not waste time switching to manual focus mode.

Common manual focus errors

  • Changing the shooting distance after focusing. Remember that when you change the shooting distance, focus will be lost. It is enough for you (or the subject) to move closer or move back (even a little), as the focus fails. This is especially critical when shooting with a shallow depth of field: portraits, close-ups ... After you focus manually, do not hesitate - take pictures right away! Remember that each new frame will require a new focus from you.
  • Choosing manual focus when it is inappropriate. Not knowing how to set up an autofocus system, many novice photographers just turn it off and try to focus manually when shooting some scenes that are difficult for them. It rarely turns out something good. Manual focus is not very suitable for dynamic scenes, shooting reports, sports, portraits. Remember that it is often better to be able to adjust autofocus, deal with its modes of operation and the choice of focus points, than switch to manual focus.
  • The arrogance of the photographer, plus autofocus aperture optics.The main mistake of many novice photographers lies in the belief that manual focus is easy. This mistake leads to the purchase of all kinds of fast lenses (Soviet, for example) with manual focus. Say, why pay for an expensive autofocus portrait, when for three pennies you can buy an excellent portrait lens with manual focus. Due to the arrogance of the photographer from the shooting, 2-3 sharp frames out of a hundred can be obtained. The reason is that in the viewfinder the camera will not be visible at all, as if you were focused or missed. The focusing accuracy through the viewfinder can only be estimated very approximately. “But photographers used to focus with this optics before,” the reader can say. You must understand that before the cameras were different, more adapted for manual focus. They (or rather, their viewfinders) were equipped with special focusing screens that can significantly increase the accuracy of manual focusing. And the technical requirements for images in those old days were lower, so rarely anyone paid attention to small flaws in focusing.
Nikon D80 Typical focusing error when working with manual aperture optics. In the viewfinder, the cat seemed quite sharp. As you can see, in fact, he is far from sharp.
Manual focusing with high-aperture optics is complex and requires a firm hand and strong nerves from the photographer. In my opinion, focusing manually with a fast lens is most convenient in Live View with zoom. In general, for shooting portraits, I definitely recommend using autofocus lenses.

Instead of a conclusion

The ability to focus manually is an important skill for the photographer. He will help him out in difficult shooting situations and when shooting on equipment without autofocus. I hope this article has helped you become familiar with the topic of manual focus. To learn how to quickly and accurately focus manually, you need practice, training. Do not deny yourself the pleasure of going on a photo walk! For your works, be not a lawyer, but a critic - then each time they will become better and better!

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