About focusing

For a modern photographer, it is vital to be able to get the camera to quickly and accurately automatically focus. In this note, I’ll give my thoughts on working with auto focus. for simple scenes using the optical viewfinder.

About focusing

About focusing

The focusing process is called differently by different photographers: focus, focus, focus, get into sharpness, achieve focus, achieve focus, catch focus. When communicating, I most often use the word 'to focus', which creates two meanings at once - to' focus' the camera to achieve optimal sharpness and to 'focus' the photographer on the subject.

Each individual camera and lens needs its own approach and ability to work with them, and such a skill comes with experience .. Also with experience comes a skill that allows you to take sharp shots of almost any task, even with slow-focus cameras or lenses.

I usually allocate focus for two types of tasks - complex and simple. I call simple photo tasks, where the subjects of the shooting move quite slowly, or even stand still. Such tasks include studio, landscape, portrait photography, partly macro photography, subject photography. I call photographic tasks complex, where the subjects are moving fast enough, where you have to often change the composition of the frame, and the shooting conditions may not be the most successful. Such tasks include photography of sports events, night photography, reportage photography, photography of children and animals, and other dynamic scenes.

Depending on the type of shooting, your own approach is developed. I usually notice that for simple tasks, amateur photographers use this focusing method:

  1. focusing on the center point on the subject
  2. frame composition (moving the camera to achieve optimal composition)
  3. shooting (shutter release)

This method is very simple and available at any CPC. For example, we shoot some kind of stationary object (in the photo below it is a plant stem with fluff). Focus is focused on the center focus point (stem is in the center of the frame), after which the focus position is locked, and the camera is rotated to compose the frame (stem to the right) and release the shutter.

focusing

I focused on the fluffy stem in the central area of ​​the viewfinder, then arranged the frame in such a way as to get a more interesting composition, where the fluffy stem is on the third of the frame line.

This is a very simple and good method of work. In this case, the center point (or area) of focus is used, which is usually best able to determine the correct sharpness of the picture. This is due to the fact that usually the central focus points are cross-shaped points (Canon is much more complicated, information here), while all the others are of linear type. Almost all consumer digital cameras have only one or a few cross-shaped dots, which are located in the center of the optical viewfinder.

The easiest way to use this focusing method is when shooting in AF-S / One Shot mode (once pressed - once focused). In this mode, after a successful focusing, the camera stops the focusing process, after which you can rotate the camera for any frame composition and the camera will not continue focusing.

However, this method has a serious drawback. When you recompose the shot, focus may be lost due to the camera changing its position in relation to the subject. Even if you rotate or move the camera a little, then it moves with it and RIPcapturing or cutting off parts of the image in the zone of sharpness. The image will help to better understand this:

Field of sharpness

Sharpness area. When the frame is recomposed, the XNUMXD 'frame' responsible for the depth of field also moves. Thus, parts of the image we need can 'fall out' from it. The plane of the frame is parallel to the focal plane of the camera (i.e., parallel to the camera sensor).

Focusing will not go wrong only when we move the camera strictly in one plane parallel to the camera matrix, for example, strictly left / right, or up / down. Errors from RIP displacement during rearrangement are often imperceptible, but using high-aperture long-focal lenses, you can actually face such a problem at close and medium focusing distances. Due to the fact that the error when recomposing the frame is often reduced to zero, this method of focusing recommended for beginner photographers.

Also, 'old school' photographers very often use this method of focusing, since the first autofocus cameras had only one central focus point and this method just became a habit.

For simple tasks, I use a different focus method:

  1. center focus pre-focus. In this case, I just focus approximately to see what is happening in the frame.
  2. frame layout. I arrange the composition of the frame as I need.
  3. select the desired focus point. I do this using the controls on the camera.
  4. focus on a key subject... There is always a key subject in the photo, which should be sharp, no matter whether it is a landscape or a portrait.
  5. shutter release.

This method gives me almost 100% confidence in the accuracy of focusing. I also like to use this method for the following reasons:

  • I always know exactly where the rip will be.
  • I can use tracking focus AF-C, even with a small movement of the subject or moving my camera with me - the camera will automatically adjust the focus. This is a key difference from the first focusing method.
  • can use spot metering exposure immediately on that objectfocused on. Spot metering exposure on Nikon cameras combined with the focus point.
  • My Nikon cameras can automatically and quickly enlarge the portion of the image I want right after taking a shot. If I focused on one point, I can instantly check the sharpness of the resulting image. In the case of focusing on the central point, and the subsequent recomposition of the frame, you will have to zoom in and out for a long time and scroll to the desired element. For example, in portrait photography, I often focus on the subject's eyes. After the shutter is released, I can immediately check the sharpness "by the eyes" (the selected focus point), this saves a lot of time when checking the quality of pictures.

Many people argue that it is wrong to use additional focus points, because these points are usually not cross-shaped and give inaccurate focusing. From my experience, I can say with confidence - all this is nonsense, modern cameras do an excellent job of focusing at any point.

Eye focus

Eye-focusing.

A minor drawback of this focusing method, I consider the fact that I have to spend time trying to select the focus point I need with the camera joystick. To save time, I configure the function of looping the focus points on my cameras, and program one of the keys to quickly return the focus point to the center. Another disadvantage is the fact that the optical viewfinder is usually very poorly covered with focus points, and there are no points at all at the edges. If you really need to focus on an object that is outside the coverage area of ​​the focus points, then I use the first focus method :) The number of focus points can always be increased using the Live View mode, in this mode they become an almost infinite number (but the focus speed decreases ) :)

Difference in frame coverage areas

It is seen that the focus points Nikon D600 knocked together in the center JVI.

For simple tasks, almost always, I use one-point focusing. When I use autofocus using all focus points, the camera can display multiple focus points at once that are "caught" in focus. But in reality, this “ripple” of dots in the viewfinder only interferes with simple scenes. The lens has only one plane, which is reflected in the depth of field in the image, therefore it is much easier to focus only on the point "pointed" to the key subject of the shooting and take into account the possibilities of depth of field.

But for complex tasks there will be a separate note on working with focus.

I advise you to look at intersecting articles:

  1. Depth of field and hyperfocal distance.
  2. Focus modes on Nikon cameras.
  3. Focus Bracketing
  4. Focusing systems on Nikon cameras.
  5. Set focus traps for Nikon cameras.
  6. AF-assist illuminator with 'spotlight' flash.
  7. How to focus on old autofocus lenses.
  8. Speeding up single-point focusing.
  9. Programming the AE-L / AF-L knokpi to lock the focus.
  10. Restructuring AF-S, AF-C modes when working with an external flash. Features backlight focusing.
  11. The viewfinder size affects the convenience of manual focus.
  12. Dependence of the viewing angle of the lens on the focusing distance.
  13. Tracking autofocus with Lock-On.
  14. Focus modes 'A / M' and 'Memory Recall'.
  15. About focus speed with non-motorized lenses
  16. Nikon entry-level cameras and focus priority
  17. Focus Features 'A', for some Nikkor lenses with the 'A-M' switch

Thank you for attention. Arkady Shapoval.

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Comments: 105, on the topic: About focusing

  • Sergei

    Dear Arkady, I once read a detailed translation of a foreign article on the principle of autofocusing (how it all works). It seems that the link to this article was either in the comments, or in your article. Many people spoke with admiration and gratitude about the article - I opened my eyes to some not entirely clear nuances of the autofocus principle. Please, if you remember about this article, please reset the link. Thanks.

  • Sotnic

    Hello, Arkady. Thank you for your work and a very useful and interesting website. After reading a lot of your articles about focusing and your review of the new Sony ILCE a7 mirrorless cameras ... (Helios series) in conjunction with ILCE a7 + Sony NEX-M42 adapter + Helios 40-2 lens?
    Another option: ILCE a7 + LA-EA4 + A-mount adapter -M42 (with a dandelion chip?) + Helios 40-2 lens?
    Or, when working with manual lenses, you should forget about all the "bells and whistles of Sony cameras" when focusing in any operating modes (A, M)?
    Creative luck, Alex

    • Lynx

      Focus Peaking and Norm.

  • Svetlana

    Arkady, good afternoon.
    Thank you for your sincere interest in the topic of photography, and contribution to the detailed coverage of complex issues.
    I would like to ask, are you planning to write an article on complex focusing methods?

    If there is an opportunity to consult with you on Skype (for a fee) on those. the nuances of photography (I have Nikon D600).
    I wish you prosperity, creative inspiration and a great financial flow;)

  • Alexey

    Good day, Arkady. I have such a question, when shooting a full-height portrait, I select the focus point with the joystick (I focus on the model’s face), after composing the frame. After confirming the focus signal, I press the shutter button to take a series of pictures (about 6-8). As a result, 1-2 are sharp, the rest are with micro-lubricants. The question is, what am I doing wrong. In AF-S and AF-C modes, the result is the same. I remove the fix on the aperture 1.4-2.5. Thank you for the answer.

  • prok

    Good day to all. I could not resist not to write my comment on this article, since someone is reading this and studying. I do not want to offend the author of the article, but I get the impression that the author, or a bad teacher, either re-read something and didn’t read something. In addition, if you are already posting training material for beginners, then be so kind as to post it in full, not the fifth through the tenth, and be consistent in your conclusions, and do not contradict yourself. A beginner cannot read between lines. For example:
    1. Your phrase: - "Due to the fact that the error when recomposing the frame is often reduced to zero, this method of focusing is recommended for beginner photographers." What nonsense ???
    2. Each autofocus mode is designed and used by all under different shooting conditions.
    3. Your phrase: - “Focusing will not be lost only when we move the camera strictly in one plane parallel to the camera matrix, for example - strictly left / right, or up / down. Errors from displacement of depth of field during rearrangement are often invisible, but using fast long-focal lenses you can actually face such a problem at close to medium focusing distances. " In this life everything can be, for this there are tripods, monopods, chairs, trees, etc. and also brains that will help you find a way out in different situations.
    And on a subject a question. A shooting subject at 10 meters, an 85mm lens, f1.8, after focusing, when I recomposed the frame, I leaned a few centimeters, will the shooting subject be in focus? And the same with f5,6 ??
    4. Your phrase: - "Many people argue that it is wrong to use additional focus points." Well, who, who so claim, what nonsense.
    PS The Internet is cluttered with all sorts of nonsense, so filter the information and be careful about the choice of teacher.
    Good luck to everyone and good shots. With uv.prok)))))

    • Alex

      In your comments, I saw a bias towards the author. He is right in his short statements. And you find errors in the line space. If you know a little more, try to express it clearly…. And you won't succeed. Go to brains, choose a teacher, filter information ... it's all from your non-intelligence.

    • Vladimir

      Prok, I can't agree with you ...
      Firstly: in your words, the author of the article had to download instructions for several Nikon cameras of different classes and dump them in the place of the article, so that, as you put it, “spread it in full, and not the fifth through the tenth”. Every sane person understands that this kind of article (to which these comments) are the thought or thoughts of a person, in this case Arkady, about some nuances from theory and practice in photography. And to the credit of the author that such people just do not "litter" the network with either copied volumes of instructions, or generally not practical things.
      Secondly: at the expense of practicality, so not a single (or rather more than a dozen) Arkady's advice, I (and if we take into account the reviews of thousands of people, not just me) practically applied and got the desired result.
      And thirdly: maybe you have at least half of such not a small experience in "communication" with photographic equipment, and the practical work of a photographer like Arkady? So I will be happy to visit your site, but I have never heard of this (except for the usual prok advertising site of the photographer, in which an ordinary wedding photographer advertises himself and his robots, and which I don't even know if it belongs to you).
      But the main thing, Prok, is that for some reason it was you who became interested (and if you already wrote a comment, you were very interested) in the Radozhiv site, and not Arkady in your site (if you have a site at all.
      PS So who needs someone in this life, the one who is following or the one who is being followed?

  • Angelina

    Thank you for the article! For a long time I could not understand why when rearranging the frame using AF at the central point, the objects are out of focus even with closed apertures, that is, with the increase in flu, I’m just shooting at fast apertures. And I’ll try according to your advice use autofocus activation with the AF-On button. Thanks again!

  • Alexey

    Such a question: on a manual lens, when focusing, I focus on the green dot in the lower right corner of the nikon D600. Do I need to point the center point to a focus object or phase sensors with a joystick and so do they suggest across the field?

    • Arkady Shapoval

      For non-CPU lenses, only the single-point focus mode is always available. Which point to set, the green dot will respond to.

  • Alex

    Good day! Tell me, the focus has strayed at three points, it gives the front focus. The rest still works just fine, blowing the sensor does not help. To give to the service, to lose equipment for a month, there is no desire. Tell me, have you encountered such a problem? Nikon D600, lost the ability to use 3D tracking, tk. when these three points are hit, the selected object is defocused.

  • Alex

    Error screen post above

  • Jury

    Dobry day usim. Be affectionate, please dear in Kiev, you can see how to adjust the camera. Dyakuyu for vіdpovіd.

  • anonym

    really crazy statements are present. how exactly in parallel can you move the camera at least a couple of tens of centimeters? IN ALL CASES, you will move the camera along a radius that may be smaller or larger. No, of course, if you use a precision robot to move, then such an opportunity will be present, and so in any case you will rotate the matrix.
    and, the photo with “focusing on the eyes”, in my opinion, is a frank soap soap, rather suitable for a sample “how not to do it”.

  • an25673

    Hello, tell me when shooting several people standing next to the F8 aperture, can I focus on the chest of one person, will there be sharpness in the face or do I need to focus on the face, eyes?

    • Oleg

      It all depends on the depth of field, which, in turn, depends not only on the aperture value, but also on the distance to the subject and the focal length of the lens. In the general case, at f8, the depth of field should be quite significant, and it should be enough for sharpness in your case.

    • Valery A.

      Google “depth of field calculator” and see what parameters of depth of field survey will be 0,5-1m at your distance.

  • an256

    Hello, tell me please, but with manual focusing, you also need to focus on the focus points, i.e. if I first select the center point by pressing the shutter button, then rotating the focus ring on the lens, will I get the sharpest photo in that part of the frame where the center point was?

    • Arkady Shapoval

      yes all the same

  • an256

    And do you need to keep the shutter button pressed in the floor while turning the focus ring or just press, select a focus point, release the button and focus manually?

    • Arkady Shapoval

      The green confirmation dot also works without half-pressing (it works while the metering is working). About working with manuals here here in detail (section “how to focus")

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Russian-version of this article https://radojuva.com/en/2013/10/focus-i-love-you-i-ll-kill-you/