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Autofocusing on Subjects

Lesson 47 from: Fundamentals of Photography 2016

John Greengo

Autofocusing on Subjects

Lesson 47 from: Fundamentals of Photography 2016

John Greengo

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Lesson Info

47. Autofocusing on Subjects

Next Lesson: Manual Focus


Class Trailer

Class Introduction


Welcome to Photography


Camera Types Overview


Viewing Systems


Viewing Systems Q&A


Lens Systems


Shutter Systems


Shutter Speeds


Choosing a Shutter Speed


Shutter Speeds for Handholding


Shutter Speed Pop Quiz


Camera Settings


General Camera Q&A


Sensor Sizes: The Basics


Sensor Sizes: Compared






Sensor Q&A


Focal Length: Overview


Focal Length: Angle of View


Wide Angle Lenses


Telephoto Lenses


Angle of View Q&A


Fish Eye Lenses


Tilt & Shift Lenses


Subject Zone


Lens Speed


Aperture Basics


Depth of Field


Aperture Pop Quiz


Lens Quality


Photo Equipment Life Cycle


Light Meter Basics




Histogram Pop Quiz and Q&A


Dynamic Range


Exposure Modes


Manual Exposure


Sunny 16 Rule


Exposure Bracketing


Exposure Values


Exposure Pop Quiz


Focus Overview


Focusing Systems


Autofocus Controls


Focus Points


Autofocusing on Subjects


Manual Focus


Digital Focusing Assistance


Focus Options: DSLR and Mirrorless


Shutter Speeds for Sharpness and DoF


Depth of Field Pop Quiz


Depth of Field Camera Features


Lens Sharpness


Camera Movement


Handheld and Tripod Focusing


Advanced Techniques


Hyperfocal Distance


Hyperfocal Quiz and Focusing Formula


Micro adjust and AF Fine Tune


Focus Stacking and Post Sharpening


Focus Problem Pop Quiz


The Gadget Bag: Camera Accessories


The Gadget Bag: Lens Accessories


The Gadget Bag: Neutral Density Filter


The Gadget Bag: Lens Hood and Teleconverters


The Gadget Bag: Lens Adapters


The Gadget Bag: Lens Cleaning Supplies


The Gadget Bag: Macro Lenses and Accessories


The Gadget Bag: Flash and Lighting


The Gadget Bag: Tripods and Accessories


The Gadget Bag: Custom Cases


10 Thoughts on Being a Photographer


Direct Sunlight


Indirect Sunlight


Sunrise and Sunset


Cloud Light


Golden Hour


Light Pop Quiz


Light Management


Artificial Light




Off-Camera Flash


Advanced Flash Techniques


Editing Overview


Editing Set-up


Importing Images


Best Use of Files and Folders




Develop: Fixing in Lightroom


Develop: Treating Your Images


Develop: Optimizing in Lightroom


Art of Editing Q&A


Composition Overview


Photographic Intrusions


Mystery and Working the Scene


Point of View


Better Backgrounds


Unique Perspective


Angle of View


Subject Placement


Subject Placement Q&A




Multishot Techniques




Human Vision vs The Camera


Visual Perception


Visual Balance Test


Visual Drama


Elements of Design


The Photographic Process


Working the Shot


The Moment


One Hour Photo - Colby Brown


One Hour Photo - John Keatley


One Hour Photo - Art Wolfe


One Hour Photo - Rocco Ancora


One Hour Photo - Mike Hagen


One Hour Photo - Lisa Carney


One Hour Photo - Ian Shive


One Hour Photo - Sandra Coan


One Hour Photo - Daniel Gregory


One Hour Photo - Scott Robert Lim


Lesson Info

Autofocusing on Subjects

All right, let's talk about focusing on moving subjects, all right, so for canon it's AI Servo, for Nikon, AF-C. So if we have our subjects in the center, the problem with moving subjects is that they are moving and they are hard to track with a small focusing point. And so I don't recommend using a small focusing point when you're focusing on something that's moving around. And so I really like a camera that has like nine or a little bit of a zone that you can kind of put on the target. If I had to choose the size or how many brackets should I use, it depends on the subject, if I'm photographing people, I like the target about the size of their torso. All right, I don't want one too big because I might pick up other athletes and referees or other things that are going on, and I don't want it too small because then it can fall over into places where there's nothing to focus on, and so something about the size of the torso is a good thing to focus on. And if they're in the center that's...

very easy to do. Now if the subjects are off center, you're gonna have to move that group of focusing points off to the side. And so the more focusing points you have, the more leeway you have in setting something up like this. Now this photo on the right, this is not something that I chose to do spur of the moment. This is something I chose to do five or 10 seconds before the cyclist reached that point in the track. As the cyclist was coming around the bend of the track I thought okay, I think I want to have him over on the left hand side so I can see the person trailing behind over on the right hand side of the frame, because this usually takes a moment to change, and this is why one of the things that's nice to have on the back of the camera is some sort of touch pad or joystick so that you can move that focusing point around really quickly. Some of the cameras that have less good control, you're gonna have to press a couple of buttons and then change things, and so you want to have as fast a control to making this change as you can, because you're not normally gonna be leaving this on the left hand side all the time, you're gonna probably be moving it around depending on your idea for composing that shot. For a stationary subject, a subject that is not moving, we have a couple of different options. With some different repercussions to them. The first option is what we talked about a moment ago, focus lock and recompose. We got our pine cone, we want to keep it over to the right hand side because we're gonna take a really artsy photo here, it's off center here. All right, and so what we have is we have our center point is what we're focusing on because we have, that's the most sensitive point for focusing. We're gonna pull that frame off to the side. There we go, and we're gonna focus on our subject. We press halfway down on the shutter release, we go back and then we take the picture. And so that's our photo so it's very easy to do this. It just, you pick it up, focus, recompose, you take the photo, it happens almost instantly once you get used to it. And so if you want to take a second shot, well you've gotta go through the process again and it's not incredibly slow but you kind of have to go through that same rigamorol focus lock, recompose, and if you wanted to take a hundred shots of this pine cone, you would get really tired of focus, lock, recompose, it's just kind of a wasteful use of going back and forth in time. So the other option, is to move the focusing point. So now we can just move the focusing point over to the right hand side here, and we can focus and take the picture in one fell swoop, you might say. And so the first shot is a little bit slower because we have to go back and we have to move that focusing point over to take the photo. But if we want to take a second, third or any sort of subsequent shot, it's gonna be very, very quick. And so if I have decided on a composition where I am away from the center and I know I'm gonna take several shots that's when I'd move the focusing point. Generally I'd just leave it in the middle. But when I've decided I want to leave somebody or something off to the side, then I'll move that focusing point. Because then it wastes a lot less time. It's also a little bit more accurate, there is a theory, and there's my own little bit I'll add to the theory, and that is is that when you move the focusing point over, and you focus, and you move the camera point, that point of focus slightly changes. And so if I'm doing a portrait of somebody and I focus on their eye, and I move, their eye will no longer be in focus, if you have really shallow depth of field. And I believe that's incorrect. I believe it does hold the focusing point, but what does happen is that sometimes because the focusing point is so shallow, the photographer or the subject might move ever so slightly. So while you turn, you may not realize that you've moved back an inch, and that has thrown the focusing point off. And so that's what's going on when you're losing the focusing point and why it might be more accurate and safe to do this, even though this focusing point is not as sensitive, if you realize you're using this and you point it at the eye lash or something that can really grab focus, this would be the most accurate way of focusing. So let's talk about mirrorless cameras, because they have a different system, they have a contrast based system. And one of the great things about mirrorless cameras is that you're not regulated to the nine boxes or even the 173, as great as 173 is, it's not as good as, well, near infinity, and so with a mirrorless system, they don't allow you to focus way way way off to the corners but it's about 80 to 90% of the frame that they will allow you to focus on. And so one option is just the whole area, it just looks at the whole thing but it uses the same parameter, it focuses essentially on the first solid object that it can find. If there is a mosquito flying around close to the lens it's probably not gonna be able to pick that up but it's the first solid object and that's gonna be a huge box area, this will look a little different from camera to camera. And these cameras have a wide variety of systems, but in general, there will also be a group of boxes or perhaps a big box, it depends on the system and then you'll also be able to have some sort of small or single area that you can move around, and the beauty is is that you can move this around all over the place. So if we were to think about where a typical DSLR can focus, the mirrorless camera can choose so many different other areas, which I think is a big advantage in some focusing situations, it's quite nice. The other area that we can work with is a face detection system, because it has a lot more information because it's looking at the whole sensor, it can actually pick up on faces, now I think there's a little bit of a dispute as to whether people like this or not and it really comes down to what type of photography do you do and whether it works for you, and so I think this face detection works great if you don't have too many faces in there because if you have too many faces it might pick up on one face that isn't the face that you want to focus on. And so with a single person I think it probably works really good, I don't use it that much, I'm just fine using a single point because I don't have to turn it on and off, but for some people the face detection is really nice because it can track that face moving back and forth. I mean if you were trying to take a picture of me and I was kind of going back and forth here quite a bit and since I'm the only person up in this area, that would be a very good system for making sure that my face is in focus. Now, with the smart systems we're able to do some pretty amazing things with the mirrorless cameras. And so on one of the Sony cameras I just did a fast start class on, we did some field testing that's in that class where we show the camera can pick up the eye of the face. And as you move around it's got a little box right on the eye and it can track the eye. It's got a smile detection, where it will automatically shoot the photo at either a slight, medium, or big smile. And you can have someone all frowny face, and then as they smile it starts taking photos. There's another camera system, well the Sony system can do this as well but there's another system where you can register a person's face, and it's facial recognition, it knows who that person is, you input the birthday, this is for your kids, you input the birthday and it automatically adds their age to the metadata of all the photos. And it will do this for pets as well. Now, the Sony system is kind of cool because you can register a bunch of faces, and this is a little dangerous for parents here, you can prioritize the faces and it will choose one face over the other face. And so you can say well these are the four people that I want to focus on but this is the most important person so if you see two, always go to this one before the other one, and so you know this could be very helpful for someone doing band photography. You register each person in the band's face and it's gonna focus on that face. And if one of the roadies comes out, it won't focus on them. And so there's a lot of new technology that's coming about in mirrorless and we'll see more and more changes in this in the future and so this is one of those things where you want to know your camera because some of your cameras will do amazing things and you may not know about it. All right, reviewing what we've been through. We've got our single focusing mode which I think is good for general photography. We have our continuous auto focusing mode which is great for action and sports photography, and then we have an auto mode which switches back and forth. And just a little side note on this auto mode, I was working on some classes for the top of the line Nikon and the top of the line Canon camera, and I found it really interesting because I was going through the instruction manual, I have to go through the instruction manuals, and I was looking for the auto, auto AF mode. And these top of the line, five, six thousand dollar cameras didn't have the mode in the camera. And I'm like, usually when you buy the top of the line, you get everything. But they know that the professionals won't even use this mode and so they don't even include it on the cameras. Not even there. All right, so that's the focusing mode, that's one thing. And then we have where we are focusing. Are we gonna choose a single, a group, or the whole area? And what I have found is that for general photography, I use single point and single AF. And it works really well. When I'm shooting sports I should use continuous and I use the group point, if my camera doesn't have a group point, I will choose continuous and all points. Now there were other combinations that you might end up using but those are the most common that I end up using. And I think they work really well most of the time. And I don't see that changing with technology. I see it getting better and slightly getting more customized but that system works out pretty well most of the time. Now the other area that this can get a little bit more convoluted is what buttons do we press to make the lens focus or stop focusing or shoot photos? And so all of our cameras have the shutter release and on all of the cameras that activates the focusing system, but on some of our cameras, we will have potentially an auto focus lock button and an AF on button on the back of our cameras. Normally, when we press down on the shutter release, it wakes the camera up, it activates the light meter, and it focuses, so it's doing a lot of stuff with a single press of the button, and then when you press all the way down it takes the photo. If you have an AF lock button, you can press the button, the AF lock button, down to lock focus so that the camera would stop focusing. It holds that focus while you take time to recompose and press the shutter release. And in theory, this sounds like that's a pretty nice idea, I can just lock the focus any time I want. I could have the camera in continuous focus so that it's always tracking movement all the time and then I can just lock it on a subject that's still. The thing that I don't like and I think a lot of other people don't like is now I need to have one button pressed here while I'm manipulating another button and that's just a little, sometimes a little more convoluted than we want, because sometimes we're working very fast and we don't have a chance to grip the camera perfectly in order to get those fingers pressed exactly like that on the camera but it is an option that some people like, and so it's something you can take a look at and see if your camera has. Now this focus lock button on, it's gonna have different names, but it's probably a button that you may need to customize, which means you need to go into the menu system and you need to tell it I want this button on the back of the camera to do a focus lock, for instance, Nikon cameras have what's, on many cameras, called an AEL-AFL lock button. And it is normally locking the exposure and it is not locking the autofocus unless you go into the menu system and you select it to lock the focusing system and so it'll only do that if you select it so this is once again, you have to know your camera to really set it up properly. One of the most popular things that came about, this is back in the early '90s, this is something that Canon introduced and has really spread to other cameras and a lot of photographers have picked up on and there's a real division I think between people who are kind of getting started in photography and people who have been doing it for a while who've gone to back button focusing. And so the way back button focusing works is that when you press down on the shutter release, it activates the light meter, but it doesn't focus. Focusing is done with a button the back of the camera, thus the name. And so you press down on this AF-ON or back button focus to get your focus set, and then you go up and you can check your light meter and you can take pictures when and where you want to, and this is very nice because you don't need too much finger dexterity to make this work. And it's gonna help you out in a number of situations and I'll show you where. Now for instance, Nikon and Canon, they have an auto exposure lock button with various symbols and or words or letters on them, and these can be turned on to be AF-Lock buttons if you want, so if you want to do this AF-Lock option, you're gonna have to go into the menu system and turn this on and that's somewhere in your camera, you have to figure that one out on your own, okay? So, if you wanted to keep your camera in the continuous focusing mode and there are some people for instance who do bird photography, the birds are flying around and so they want continuous focusing for tracking all the birds, but then the bird lands on a branch or something, and they want to be able to kind of lock that focus in and recompose the photo, and so you could leave the camera in continuous focus, your subject is being tracked towards you and away from you. So you're continuously focusing. And then you can go over to the AF-Lock button, press down on it, and then you can recompose and have your subject off center, now it's not tracking the focus at this time, it's simply locked in in that particular area and you can take the photo. And so this is a system that has a lot of potential to it, but it's not something that I use in a lot of different areas, but just be aware that this auto focus lock must be turned on. An example of where I might use it is up in Alaska, some bears are roaming around the field and I want to get pictures of them walking around, but then they stop. And I want to put them off onto the side so normally I would be tracking their action here in the middle, but since they've stopped moving I could just press in on the lock button, recompose and get this shot. Or this, I think it's an oyster catcher, walking along, they hunt along the ground and they're picking at food and then they stop and they look around and now I can recompose and get it off to the side of the photograph. And so for those things that move and then they stop, that's one way of locking in the focus exactly as you want it. So for back button focusing, your camera needs to have some sort of AF-ON button or a button that you can program to do that, many of the Nikons will have an AF-ON button, many of the Canons will have an AF-ON button, many of the other manufacturers will have a button that may not say those words on it but can be programmed for focusing. And so in this case you're gonna press down on that button until focusing is achieved, however long that takes, usually just a second or so. And then you can go over to the shutter release and you can take a picture whenever you want, so long as that subject distance hasn't changed. Now on some cameras you need to put your camera into a back button focusing, and I'll give you a warning right now. Very few cameras actually call it back button focusing. For instance in the Nikon camera, you have to turn off the focusing of the shutter release. Which is kind of a counter intuitive way of thinking about it, and so once again you've gotta know your cameras. And so this is why this system is popular and it works quite well, let's take this landscape scenario right here. We've chosen to focus on the center point, the problem is is that there's nothing to focus on on the center point. So with the normal system we'd have to move our camera off to the side, and we're probably on a tripod so we've got to unlock the tripod, move it off to the side, press halfway down for focusing, leave our finger half way down as we're repositioning our tripod, locking it back in, and then we press the shutter all the way in. And if we want to take another photo, we have to unlock the tripod, move it over, and put it back. All right, little less trouble with if your handheld but it's still kind of that same problem. With back button focusing, what we do is we figure out what we want to focus on, point the camera at it, press halfway down, focus, and now we're pretty sure that rock is not moving. We're pretty sure that we're not gonna move any closer to that rock, we've repositioned the camera and we can continue to shoot as many pictures as we want, knowing that we have already set focus and that part of the job is done. So you focus, you're done with the job, and you move on and you can shoot as many photos as you want without having to refocus and recompose. And so for shooting multiple photos, it's less of a hassle. Which is really nice, it's nice to have things that are less hassle. Are you gonna talk about how focus lock and recomposing impacts metering or exposure? No I don't have a slide for that one. What? Can you talk a little bit about that, does it affect it? Well it depends on how far you're moving the scene, I think in many of the situations, and I may talk a little bit about this in section 10, kind of the final process of photography is usually I'm figuring out the exposure ahead of time. And it's kind of rare that the light is changing dramatically in the arena that I'm shooting photographs. And so I'm usually figuring out what the exposure is and then once that job is done, then I work on the focusing system, and once that's done then I work on composing and timing, and it's gonna depend on how you shoot and where you shoot, and I can see how someone would potentially be focusing on one thing and they're locking in so there's a number of ways to get into your camera as far as locking the focus point, for instance some cameras, something that a number of people like is they want to be able to have spot focus and spot metering, and sometimes they want to lock them and sometimes they don't want to lock them, they want to focus here, they want to meter here, but they want to compose here. And things can get very complicated in that regard and so that's why I'm usually manually getting the exposure set so that it's good wherever I want to compose. Get my focus set and then get the timing in composition.

Class Materials

Free Download

Fundamentals of Photography Outline

Bonus Materials with Purchase

Learning Project Videos
Learning Projects PDF
Slides for The Camera Lessons 1-13
Slides for The Sensor Lessons 14-18
Slides for The Lens Lessons 19-31
Slides for The Exposure Lessons 32-42
Slides for Focus Lessons 43-62
Slides for The Gadget Bag Lessons 63-72
Slides for Light Lesson 73-84
Slides for the Art of Edit Lessons 85-93
Slides for Composition Lesson 94-105
Slides for Photographic Vision Lessons 106-113

Ratings and Reviews

a Creativelive Student

Love love all John Greengo classes! Wish to have had him decades ago with this info, but no internet then!! John is the greatest photography teacher I have seen out there, and I watch a lot of Creative Live classes and folks on YouTube too. John is so detailed and there are a ton of ah ha moments for me and I know lots of others. I think I own 4 John Greengo classes so far and want to add this one and Travel Photography!! I just drop everything to watch John on Creative Live. I wish sometime soon he would teach a Lightroom class and his knowledge on photography post editing.!!! That would probably take a LOT OF TIME but I know John would explain it soooooo good, like he does all his Photography classes!! Thank you Creative Live for having such a wonderful instructor with John Greengo!! Make more classes John, for just love them and soak it up! There is soooo much to learn and sometimes just so overwhelming. Is there anyway you might do a Motivation class!!?? Like do this button for this day, and try this technique for a week, or post this subject for this week, etc. Motivation and inspiration, and playing around with what you teach, needed so much and would be so fun.!! Just saying??? Awaiting gadgets class now, while waiting for lunch break to be over. All the filters and gadgets, oh my. Thank you thank you for all you teach John, You are truly a wonderful wonderful instructor and I would highly recommend folks listening and buying your classes.


I don't think that adjectives like beautiful, fantastic or excellent can describe the course and classes with John Greengo well enough. I've just bought my first camera and I am a total amateur but I fell in love with photography while watching the classes with John. It is fun, clear, understandable, entertaining, informative and and and. He is not only a fabulous photographer but a great teacher as well. Easy to follow, clear explanations and fantastic visuals. The only disadvantage I can list here that he is sooooo good that keeps me from going out to shoot as I am just glued to the screen. :-) Don't miss it and well worth the money invested! Thank you John!

Vlad Chiriacescu

Wow! John is THE best teacher I have ever had the pleasure of learning from, and this is the most comprehensive, eloquent and fun course I have ever taken (online or off). If you're even / / interested in photography, take this course as soon as possible! You might find out that taking great photos requires much more work than you're willing to invest, or you might get so excited learning from John that you'll start taking your camera with you EVERYWHERE. At the very least, you'll learn the fundamental inner workings and techniques that WILL help you get a better photo. Worried about the cost? Well, I've taken courses that are twice as expensive that offer less than maybe a tenth of the value. You'll be much better off investing in this course than a new camera or a new lens. I cannot reccomend John and this course enough!

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