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General Stuff, Theory n Technique

Learning to Focus in Photography


Learning to Focus in Photography

There are three elements of a photograph that I consider more important than any other. I consider them such because I feel you have to nab them right at the moment you take the shot – not afterwards – if you want to end up with a good photograph. Or at least one with potential. What are these elements I speak of? Exposure, composition, and focus. Get these three elements right, and with some minor touching up – that is very possible on even the most basic editing app – you could end up with a good (or great) photograph

You might argue that exposure can be corrected to a fair degree (and more so if you shoot in RAW) when post processing. You maybe right if you do, but come on! We all want to get that exposure as close to perfect as possible, straight off the camera, right? I do, at least! But alright, even if you leave exposure aside, focus and composition are two parts of a photograph that I find near impossible to fix afterwards. So while you can change and fix many other aspects of a photograph any time after you’ve taken it, exposure, composition and focus are three parts of the shot that you do not want to have to adjust later on. Definitely not

That’s why I consider it so important to perfect these elements right at the moment you take the shot. I’ve covered the basics of exposure and composition already – check them out if you haven’t yet – and today I’ll be covering the third and last of them: focusing

Yes, pretty much every digital camera comes with some sort of autofocus system, most of them pretty fancy ones at that, and if you have anything like a DSLR, you should not have trouble achieving focus. But there are a lot of ways you could go wrong – a lot of mistakes you could make without realizing it – and therefore a lot of times when you think you’ve got focus right, but you haven’t, and you go home all satisfied, only to be extremely disappointed with one shot that has everything right but focus. To help avoid these situations, today I’ll be going through some basic, yet useful techniques that I’ve been using to get consistently well-focused images; hopefully they would have a similar effect on your own work too. Alrighty

How To Get Sharp, Focused Images

Focus your eyes! Adjust the viewfinder diopter

Let’s start with this very important, yet often overlooked point, a tip that one of my friends – an early mentor, if you will – taught me back when I was just starting out.  If you’re using a DSLR (or any camera with an optical viewfinder), adjust the diopter to suit your eyesight. This allows your own eye to see a clear, focused image through the viewfinder, as you look through it. It makes sense, doesn’t it? I mean, how can you focus correctly if you don’t know when things are correctly focused?! Before you do anything else, adjust your viewfinder’s diopter. Read your manual if you don’t know how

Circled in red, the little wheel to adjust your diopter

Circled in red, the little wheel to adjust your diopter

Once that’s done, you can go through the basics of the autofocus system of your camera 

Understand Autofocus (AF) points

AF points are those tiny little boxes on your viewfinder and are what your camera uses to detect a subject and focus on it. These are placed around your viewfinder, and each point can be used to focus on the area of the frame that it covers. These points are selectable – read your manual to find out how – and will probably turn red when activated to show which one you currently have selected. Quite easy to understand, really

AF points of a Canon DSLR - Image from Canon.com

AF points of a Canon DSLR – Image from Canon.com

AF points from a higher-end Canon DSLR - Image from Canon.com

AF points of a higher-end Canon DSLR – Image from Canon.com

To focus, compose your shot through your viewfinder. Next, select an AF point that falls around the area that your subject is in. Half-press your shutter, and the camera will lock focus on the area of the subject that the selected AF point covers. Once you have focus lock, press the shutter button fully and you’re done!

AF points come in two basic types: cross-type points and regular (single) points. Without going through too much detail over this, just know that cross-type AF points are more sensitive and therefore more accurate, so it is easier to focus using this type of AF point

Some cameras come with just the one cross-type AF point, usually in the center of your viewfinder, surrounded by many (8, 10, or more) regular points, while more expensive cameras come with, say, 19 AF points, all of which are cross-type

As cross-type AF points are more sensitive and accurate, when selecting the AF point to use, it is smart to choose a cross-type point, which will get you the most accurate results, especially in tricky (low) lighting conditions and so on. If you have just the one cross-type AF point, and it is not in an area that covers your subject, you can switch to a regular AF point that is better situated to focus on your subject…or you can use the Focus and Recompose technique, discussed below. Read on!

Either way, know your viewfinder and the AF points on it like the back of your hand – know which ones are regular, which ones are cross-type, and how many are there, and how they are spread out –  so that when necessary, you can change them without having to stop to think

NOTE: Not only pricey DSLRs come with these selectable focus points. Almost all new compact cameras (at least the higher end ones) come with selectable focus points too. Make sure you know how to use these!

Know your camera’s AF modes

Cameras usually have two basic AF modes: Single Focus and Continuous Focus. On Canon cameras, they are known as One Shot Focus and AI Servo respectively. On Nikons, they are dubbed Single Servo and Continuous Servo. Other brands have probably titled these modes similarly, but you will have to figure that out. There are probably more modes on each camera, but these two are basic ones that any camera will have

The AF mode selector on a Canon camera - Image from Canon.com

The AF mode selector on a Canon camera – Image from Canon.com

Anyway…the difference between the two? Well, using Single Focus, you half-press your shutter button, and the camera uses the selected AF point to detect the subject and its distance from the camera, and locks focus on it. As long as the button is half-pressed, the camera remains focused on that distance i.e. it is focused at that single distance, for a single shot

Using Continuous Focus, you place your subject in the camera’s ‘tracking’ area (read the manual!), and once you half-press the shutter button, the camera will begin to track this subject, continually focusing on it, even if it moves. The focus is never ‘locked’ as such, but is continually active and changing as it detects movement of the subject. This way, you can continue to click and capture multiple images that are all focused, without having to re-focus between each shot

I think this is rather obvious, but let me break it down anyway: Single Focus is ideal for stationary subjects, while the more power-consuming Continuous Focus mode is best suited for moving subjects 

Stop using the Multi-Area AF mode

A sub-mode of the Single Focus mode, if you like, this mode – usually titled Multi-Area AF mode on most cameras – uses all the AF points that your camera has at once, and attempts to detect your subject and focus on it for you. This is not what you want. You’re the photographer – you pick the subject. Turn this stupid mode off, and pick a single AF point. Place this over your subject, the subject that YOU know to be the one you want to focus on, and half-press your shutter button to focus. That’s what you should be doing! Using the Multi-Area mode, the camera might assume the large chair in the background is the subject, and not the person standing to the side

Decide where to focus

Alright, so you know what focus points do. You know what AF modes there are. You know you should pick a single (preferably cross-type) AF point. Now what? Pick a spot on the subject, place the AF point over it, and focus! Right?

Sure, but knowing to pick the right spot on the subject is an important part of it. You see, AF points work by detecting areas of contrast on your subject. That’s part of how it judges how far the subject is so that it knows where to focus. So placing the AF point over a spot with little or no contrast would mean that even a good AF system would struggle to lock focus. For example, if you’re shooting a stationary black car, placing the AF point over the plain black paint of the car door, for example, will result in the camera struggling for focus. It probably would never focus if you keep pointing it there. However, if you move the AF point to an area where there is contrast i.e. contrast between the black paint of the door and the silver of the door lock, your camera’s AF system should handle that pretty much instantly

On the left: bad, low-contrast spots to focus on. On the right: good, high-contrast spots to focus on

On the left: poor, low-contrast spots, spots you should not try to focus on. On the right: good, high-contrast spots that you can use to focus on

Focusing on the plain color of a person’s shirt might not work well, but if you move your focus point to the person’s face, where there is contrast between skin, eyes, hair, etc., that should work fine

So yeah, picking the spot to place your AF point when focusing really determines the speed of which you will lock focus. It will also get you consistently accurate results

Focus and Recompose

Alright, you’ve probably heard of this technique. It gets a lot of stick from some people, while some people find it works perfectly well. I’m in the latter group. Either way, what does it do? What does it involve? Why use it at all?

Imagine this. You have picked the center AF point on your viewfinder, as it is the only cross-type one and is most accurate. However, your subject is not in the center of the frame. It is more towards the lower right corner of the frame, and you want it to remain that way, to achieve a nice Rule of Thirds composition. What do you do?

You have two options. First, you could select another AF point, one that is closer to the subject, and use that to focus. This could work, but then again, it might not. You might not have an AF point that is near the subject, and even if you do, it might not be a cross-type point, and might struggle to focus accurately. Besides, it takes time to change AF points, and you might not have this amount of time

The other option is to focus and recompose. How? Simple. Point the center AF point at your subject. Half-press the shutter button till you lock focus. Then, still half-pressing the shutter button, you RECOMPOSE your shot so that the subject is back at the right place (on the lower right corner of the frame) and once you’re happy with the composition, you complete the shot by pressing the shutter button completely. Job done. As the focus was locked on the subject, and continued to be locked as you recomposed the shot, the final photograph should have your subject in focus, and in the exact place you wanted it to be in the first place. Brilliant, right? Yeah. You probably know of this technique already, but I had to mention it here. I use it very often

The best I could do to describe this. On the left, see how the subject (man on bike) is centered, and covered with the red focus point. Focus is locked at this point. After that, with the focus still locked, the image is recomposed, to place the subject at a nice, Rule of Thirds position, while still maintaining focus

The best I could do to describe this. On the left, see how the subject (man on bike) is centered, and covered with the red focus point. Focus is locked at this point. After that, with the focus still locked, the image is recomposed, to place the subject at a nice, Rule of Thirds position, while still maintaining focus

Why do some people avoid this technique? Well, in theory, it doesn’t sound like it would be too accurate. Why? Because when you first point the camera at the subject (using the center AF point) and lock focus, the camera locks focus to that particular distance. It detects the camera-to-subject distance, and tells the lens to focus there. However, when you recompose your shot, the camera-to-subject distance marginally changes, meaning that when you take your final shot, the camera is not focused exactly on the subject any more – it is still focused at the original distance – which means that, technically, the focus would be slightly off in your final image. Yes, it is a very marginal change in distance, but it sounds like it could be enough to affect accuracy, right?

Well, that’s up to you to decide. You can be like many others, and take this theory as it is and believe it. Or you could believe the rest of us, people who’ve tested this theory repeatedly, in many different situations, and found this error to be absolutely negligible. Really

I find that using the central AF point – which, even in the best camera, is the most accurate one – along with the Focus and Recompose technique to work almost all the time, and works far better than having to change the AF point to less accurate ones everytime I want to shoot an off-center subject. It’s faster too. This is how I take pretty much all my shots. Do not be afraid to try this technique. It’s perfectly accurate, and really works!

Do not move your camera after focus is locked

Like I said in the previous bit, moving the camera after focus is locked will mean focus in your final shot will be off. Moving the camera slightly to recompose your image is usually fine, as (like I just mentioned) the error in this case is negligible; but moving your camera directly towards or away from the subject will cause the camera-to-subject distance to vary significantly, and this will cause serious focusing errors. So whatever you do, after you lock focus, do not move your camera. If you do, focus again

For landscape photography, use the Hyperfocal Distance

The hyperfocal distance is defined as the closest distance to which you can focus your lens while keeping objects at infinity appear sharp. When focused to this distance, everything from half this distance all the way up to infinity should be in focus. Acceptably sharp focus

Most often, having everything in sharp focus in a landscape is very desirable. Right? Therefore, shooting at the hyperfocal distance, which gives you just that, is ideal for this type of photography, isn’t it? Yes it is

The calculation of this distance is not something I’m going to be covering here today, but there are plenty of articles (and automatic calculators, I believe) that will help you out in this regard. Google it! Once you know more about it, and you know how to calculate this distance for your lens and its focal length, simply focus this lens to the hyperfocal distance, and watch the magic unfold!

If you have no way of calculating it on the spot, a safe bet for distant landscapes is to focus your lens to infinity. This should ensure that almost everything in the frame is in sharp focus

To focus to the hyperfocal distance or to infinity, you can use your lens’ distance scale and focus manually; but if you want to focus automatically at some spot, remember to make sure it has decent contrast!

For portraiture, focus on the eyes

I talked earlier of picking a spot to focus on. In landscapes, focusing at the hyperfocal distance is usually ideal. In portraiture, however, focusing on the eyes is what is considered most desirable. Get the eyes focused sharply, and everything else seems to fall into place. It just works. Don’t try to figure out why it is such. Just know that it is so! And as eyes have plenty of contrast, any AF system will lock focus instantly!

In another cases, focus on what you want

Rather obvious. If your photograph does not fall into the landscape or portrait category (and of course, many wouldn’t), focus on whatever part of the scene you want to be in focus. Just place your selected AF point over this spot and half-press your shutter button. Recompose if necessary, and shoot

Try Manual Focus

In some situations, if things are too dark, and/or not contrasty enough, your autofocusing system might not be able to cope, and you may need to switch to manual focus. Focusing manually can often be slow, but this is sometimes the only option you may be left with. Just make sure you are aware of how much time you have to get it done, and practice – you’ll soon get faster at it. And unless you have a suitable focusing screen, I recommend you try manual focusing through your LCD, where you can clearly see, and zoom in, so that you know when your subject is in focus

Focus twice on the subject

If you have time, focus twice on the same subject. This will maximize AF accuracy, and will negate any errors that the AF system might have made due to reasons you might not realize at the time

Watch your shutter speed

If you shoot handheld, make sure your shutter speed is fast enough to do so. A common error is to shoot at a slow shutter speed, and then mistake the blurry result of camera shake for an out-of-focus image. If you need to shoot at a slow speed to get the right exposure, of course…use a tripod!

Be Critical

Lastly, once you’re done with your shoot, examine your shots on your computer very critically. Zoom into each one – 100% is ideal – and make sure the subject is in perfectly sharp focus. If it isn’t, delete or discard it. I know it can be very depressing to get a really good shot only to find it is slightly out of focus, but trust me, you do not want to keep these. Having such images in your collection, and sharing these, will only make you appear rather amateurish. It’s true. Be critical of your work, always…and if your best shot of the shoot is not in focus, use that as a lesson and do better next time!

And that’s all I have for you on the topic. Focusing is an absolutely critical part of photography, like I mentioned in the beginning, and I’m rather embarrassed I kept putting off writing this important article until now! Anyway, I hope you learned something new from this post. A lot of this is pretty basic stuff, but there’s always something you can learn even by re-reading the basics, so I hope I managed to pass something across!


Leave a comment if there’s anything you’d like to ask, or if there’s something you’d like to add. I’m sure there might be some comments about the Focus and Recompose thing – so let me just clarify that what I mentioned on this technique is my opinion! Don’t go bashing me on that! Alright then. Thanks for reading. Until next time

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By Heshan Jayakody
All content in this post, including images, is my own, except where noted
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Discussion

26 Responses to “Learning to Focus in Photography”

  1. hello! wonderful post! just came across it today and wow, it’s excellent. so useful for beginners like myself. i’ve always been having trouble getting perfect sharp photos. maybe the trick is here in one of your tips. i’ll be trying them all out! thanks!

    Posted by Yan | February 19, 2013, 07:51
    • thanks Yan. i just shared this post today, and i’m glad you found it already. i really do hope some of these techniques help you achieve perfect focus consistently – it can be so annoying to get a really good shot that’s slightly off focus. especially with portraits!

      Posted by pixelogist | February 19, 2013, 08:10
  2. useful post! i love some of these tips. the diopter tip is something i never thought about in relation to focusing, although i have already set mine up right. i’ve been using focus and recompose a lot too, and i think most of my shots end up well – focus-wise at least! thanks for sharing these tips, it gives me more confidence to use them when i know experts are using them too!

    Posted by Allan | February 19, 2013, 17:10
    • Thanks! Yes, the diopter isn’t something people often think about in relation to focus, as you say – they usually set it up so they can see the image and conmpose clearly, but it is also a huge part of getting accurate focus! you’re welcome Allan, thanks for your kind comments!

      Posted by pixelogist | February 19, 2013, 18:17
  3. I second “Try Manual Focus”. That is almost all I do nowadays and it has made me much more aware of where I put the focus and, as it takes some extra time, also allows me to think a bit more on the composition.

    Posted by jabcam | February 21, 2013, 02:38
    • Hi jabcam, not seen you here in a while, thanks for commenting! I have to admit I use autofocus a lot, but you make a great point. If I always had the time to focus manually, it really gives the most control. Of course, my old film SLRs make this choice easier, where there isn’t autofocus! But then again, these cameras are designed to do so, with their rangefinder focusing screens etc., so I’m actually pretty fast to manual focus with these. But with most DSLRs, I find myself pretty slow. If you have any manual focusing tips, please share!

      Posted by pixelogist | February 21, 2013, 06:08
  4. interesting post! i rarely use manual focus as it is much slower for me. but i guess there are times i could try to use it. focus and recompose – i was worried after reading some people’s thoughts on it, as they really condemned it, so i was glad to read your take on it. really makes sense

    your “Focus Twice” technique is curious too. i guess it makes sense, but may i ask why you recommend this? thanks, btw, for sharing this wonderful collection of info, here and all across your blog

    Posted by Will G | February 21, 2013, 15:39
    • Thanks Will :) When you have time to focus, focusing twice on the subject (half-press the shutter button twice at the same spot) will reduce any mechanical errors that the lens could create when focusing. For example, when your lens is focused very near, and you suddenly focus it on something distant, the mechanics of the lens can sometimes drive the final focal point slightly off the correct point. Focusing twice will cut down this error pretty much completely

      Manual focusing definitely has its moments, and like i said, it depends on your focusing screen too. Focusing with a DSLR through the viewfinder is not only slow but can be rather inaccurate (I find) – Use the LCD if you’re shooting digital. And make sure you have enough time! If not, AF is the way to go

      Posted by pixelogist | February 21, 2013, 17:10
  5. great tips! thanks for sharing :) really enjoyed this read. it helped me a lot

    Posted by James | March 5, 2013, 20:55
    • No problem, James – glad you found it useful. There’s a lot more similar posts on basic theory of photography, keep browsing pixelogist!

      Posted by pixelogist | March 6, 2013, 12:27
  6. Understanding focus is so important in photography. I agree that it is absolutely vital to get it, and composition spot-on. Exposure too. Right at the moment you click. Most people do not get the importance of it, and rely too much on the ‘brain’ of the AF system

    Posted by Umar | March 7, 2013, 09:51
    • Absolutely. The AF system is only as good as the person using it (or something like that!) haha. You need to understand it well enough to get the most out of it. Don’t blame your camera when your pictures are out of focus. Blame yourself, and work at getting it better!

      Posted by pixelogist | March 7, 2013, 12:46
  7. Very helpful tips! I was afraid to use focus and recompose after reading some articles about it. So you really have found no errors with this technique? The other tips are superb too, thanks!

    Posted by Shane | April 20, 2013, 08:29
    • I’ve been using the Focus & Recompose technique since Day 1, and never had any noticeable issues in focus accuracy. That’s not to say that I’ve never taken a shot that didn’t hit the mark perfectly, but I can’t say I’ve noticed focus errors that happened solely due to the Focus & Recompose technique

      Posted by pixelogist | April 20, 2013, 10:37
  8. This post, and a few others, helped me no end! A few others from your blog helped me a lot too! There’s so much to know about photography, and one doesn’t sometimes know where to really start. Thanks so much!

    Posted by Gerry | May 8, 2013, 15:29
    • Glad to have helped, Gerry! You’re most welcome – thanks for stopping by to comment. Keep following pixelogist – I plan on doing a lot more of this type of posts as and when I think of topics to write about. If you have any suggestions – something you don’t understand – let me know, I might just do a full post on it!

      Posted by pixelogist | May 8, 2013, 18:11
  9. All this is based on how good an AF system my camera has too, right? Thanks for the tips, but I’m wondering how much they will help if my camera isn’t fast enough to be gin with?

    Posted by Ted | May 10, 2013, 16:29
    • Well, not really. These techniques are primarily aimed at improving your focus ACCURACY, not just your focus speed. No use focusing in a split second if you focus on the wrong thing, right? Know how to focus exactly where you want to focus on – that’s the most important part. A fast AF system, along with proper technique, will also make sure you lock focus faster, which is important when it comes to shooting moving subjects – but for me, the most important thing is to make sure you accurately get focus exactly on your subject – consistently. Speed is only necessary for some styles of photography. Focus accuracy is necessary for every style

      Posted by pixelogist | May 10, 2013, 21:29
  10. Great tips. Thank you very much for sharing all this. I’ve been reading many photography books as well as blogs. Yours is one I’ve recently bookmarked. Thanks

    Posted by Zack | June 24, 2013, 07:04
  11. Hi, I have a question about deciding the AF spot. In your example photo, there is an AF point over both the column and the wall behind. I think it only works if you want both the wall and the column to be in focus, right? However, if I want to focus on the column only using a single AF point, should I choose a point that lies completely within the column? (As far as I understand, camera focusing works by measuring the distance between the subject and camera, so if I want to focus on only one subject, I have to choose an AF point over that subject or a spot that has similar distance.)

    Posted by Thalia | August 2, 2013, 15:45
    • Hey, thanks for your comment. To answer your question: even if the AF spot covers two subjects, it doesn’t mean that it will be able to focus accurately on both subject if they are distanced differently. In this case, the wall is some distance behind the column, so even though the the AF point covers both, it will either focus on the wall or on the column, depending on how you focus. My diagram’s red boxes actually show the high-contrast areas you should use to get accurate focus – they’re not actual AF points. AF points are much smaller, and usually will not cover more than one subject. Just choose the closest AF spot to your subject, and move it until it covers the subject you want to focus, and shoot

      Always remember that if there are two subjects and they are at two different distances from the camera, you technically cannot focus on both of these. You can focus on one, and hope that the ‘depth of field’ covers the second subject (read my post on depth of field for more on this!), but you always focus on just the one. Choose your AF point and get the subject you want in focus. Hope this helps!

      Posted by pixelogist | August 3, 2013, 18:26
  12. Hi,

    I have a question that i’m hoping you can answer for me..

    I’m shooting with a Nikon D7100 with a 18-300 f3.5

    If I compose a shot at say 50mm use the cross point autofocus point it appears sharp. When I look at the same point at 300mm without moving the focus ring or autofocus setting the object it is not in focus.

    What I have been doing is zooming in on my focus point to 300mm, allowing the camera to autofocus and then setting the proper focal length for my composition and the image is super sharp.

    Do I have a problem with my lens autofocus, or is this just the limitation of the autofocus system with the glass I am using?

    Thanks

    Mark

    Posted by Mark Ishikawa | September 1, 2013, 21:54
    • Hi Mark
      From what I can understand, you’re saying this: you compose a shot at 50mm, then autofocus on your subject. Then you zoom in to 300mm, and without focusing again, you find the same subject is out of focus. Right?

      If I got your case right, then it’s perfectly normal. It’s a limitation of your lens, and many other lenses too. If you want to focus, and adjust your focal length, you need what is known as a ‘parfocal lens’. This sort of lens (usually more expensive ones, but even pricey ones are not always parfocal) remains in focus even if you change your focal length (zoom in/out)

      The best thing to do with most lenses (unless you know you have a parfocal lens) is to focus only after you’ve decided your focal length – or if you change focal length, always remember to refocus before releasing the shutter

      Hope this helps!

      Posted by pixelogist | September 2, 2013, 07:00
  13. THanks for explaining the focus/recompose technique so clearly, i’ve been confused over it for a long time and was not sure if to use it coz some people say its not good to use it. Also thanks for the explanation of the hyperfocal distance – easy to understand and short! Cheers!!

    Posted by Sergei | November 21, 2013, 15:19
    • Cheers, Sergei! Glad it helped. The focus and recompose technique is one that I use daily, and while I get the occasional out-of-focus shot, my AF accuracy is pretty good! Haha. It really is the best technique I can show anyone in the AF department. The hyperfocal distance theory is often thought of as something more complex that it is – but it’s really quite simple, and once you understand it, it can be extremely useful in some cases, especially in landscapes. Good luck!

      Posted by pixelogist | November 21, 2013, 16:47

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