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Camera Buyer's Guide

Lesson 10 of 16


John Greengo

Camera Buyer's Guide

John Greengo

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Lesson Info

10. Autofocus

Lesson Info


Auto-focus, so if you want your image to be sharp, the camera's auto-focus system is going to be able to do that, generally, very very quickly. Let's talk about some of the different things to know about. Well, to start with, you can still manually focus lenses, which is why there are manual focus rings still on the lenses, and there are some times and places where manual focus is appropriate. Some lenses have much bigger, better, more comfortable feeling focusing rings and that's something you typically get with higher end lenses. When it comes to auto-focus, it's pretty simple procedure, press down half way on the shutter release, and it's going to engage the focusing system. Release halfway, and you're back to the normal. So, one thing to think about in the auto-focus category, is the area of coverage that you have. This is one of the major advantages of mirror-less cameras, is that they can cover nearly the entire screen with these focus boxes where you can choose to focus on. Many...

of the more basic DSLRs will only have nine focusing points. Some will have many more, but generally, they have gaps between them and they do not reach as far as the mirror-less cameras. But be aware that the number of points, at this point in time, is not real important because we have some cameras with a hundred or two hundred, or five hundred focusing points. The difference between 100 and 500, I know it's 400, but it's actually not very much in the practical use. If a camera only has nine focusing points, yeah, that's something to be aware of. The area of coverage is probably more important. How big of an area in the frame is covered by focusing points? And this is where mirror-less cameras have a big advantage. Now, there is a difference in technology and performance as you get to different price levels. When you spend $500, compared to $5000, you're going to get much bigger coverage area, you're going to get a lot more points, and they're going to be a lot more sensitive, and the focusing system is going to be quite a different in there. Mirror-less cameras use a different system for focusing. They use something that's primarily considered a contrast detection system. So, it's measuring whether there's lots of contrast and it can actually see if it's in focus or not. Phase detection can determine before the picture is taken, whether the picture is out of phase and out of focus, and it directs the lens to where things should be. And, in general, the basics between these two is that, contrast detection is extremely accurate and that's one of the beauties of mirror-less cameras, is that when the camera properly focuses, it is spot, perfectly, on. The advantage of phase detection, is that it's very fast. Because of the different system, and I'm not gonna get into the nitty-gritty details in this particular course on how it works, but it is extremely fast as I mentioned before. If you're doing a lot of action photography, subjects moving around, DSLRs in general, still hold the slight edge over the mirror-less cameras, as a whole. The contrast detection is available for a wide area, and you can do other things like face and subject tracking with it. It works in the view finder and on the LCD in the back of the camera. And many of these contrast detections, also incorporate face detection into the way that they work in order to speed them up, and that's why they're being able to compete with face detection only systems. The phase detection system, which is primarily used in Nikon, Canon, and Pentax, it's been around for a long time. It's what most of the professional sports photographers are using because that's where a lot of the lenses are, and it's a highly developed system that has proven itself over time. And so, if you were going to the next Olympics, phase detection system is probably the way to go, but I'm gonna bet you there's gonna be some new mirror-less cameras that are competing with it. In fact, there's mirror-less cameras right now that are competing full on with many of the top of the line DSLRs. It's just that there's a bigger system that is changing very, very quickly. The focusing area that you choose can be all points, it can be a group of points, or it can be a single point that you can move around. So, if you're the type of person that likes to be very precise about things, you could choose a single point, and what you want to look for in a camera, is a camera that has a joystick or directional controller, so that you have a dedicated button for moving that focus point around, cause it's something you end up doing quite a bit. And this is one of the latest features that are on most of the medium and high end cameras, is a dedicated button for moving that focusing around. That can be very nice for speeding up the focusing process. There are two different ways in which a camera will focus, and pretty virtually, all cameras are gonna have these two modes. The first one, is called single auto-focus, and this is where the camera focuses on a subject, and then stops. And so, as an example, if you have the center point activated and there's no other points available for that particular subject, what you do is you point your camera over that subject so that you're focusing point is on your subject. You press halfway down, you focus lock, and then you recompose the camera into the composition that you want to capture, and press the remainder of the way down. All the cameras work as this, as a default option, and it works very good in many different cases, and that's called single auto-focus. The other type of focus, is considered continuous auto-focus and this is obviously designed for subjects that are moving towards view, or away from you, or just moving around in any direction. This is where the camera is gonna track that subject. And the idea here, is that as your subject is coming towards you, you can take numerous pictures with the motor drive turned on. The camera tracks it all, and can keep every one of those pictures in focus, and the better systems do this very, very well. This does depend a little bit on money. The more money you spend, typically, the higher end the auto-focus systems, the better performance, the higher percentage rate of the photos you're gonna get are in focus. There is a third system you could also use, and that is AF-A and this is an auto-mode And it's not really a third mode, it is a third option, but what it does is this is where the camera choosing singular continuous. And I'm not a big fan of this, because it's unclear, sometimes what the camera is going to choose, and it's easier just to switch between S and C for singular continuous, in my mind. With the new mirror-less cameras, there's a number of advanced auto-focus modes that are now becoming available, and they are improving quite rapidly. The first of these is subject tracking. You choose a particular area, and the camera will automatically determine what that subject looks like, and will follow it to other places in the frame and will track its movement. Can do anywhere from a phenomenal job, to it doesn't seem to keep track of the subject. It depends on the types of subject in the scenarios that you're in. You also have face tracking, which can identify faces and lock on faces, which is great for portrait photography. And if you want to get even more exact, you can do eye tracking, where it actually looks at a specific eye; the nearest eye, the left eye, the right eye. You can go into some cameras, and detail this. And these, are features you're gonna find exclusively on mirror-less cameras when using their electronic viewfinder. Some of the DSLRs do have these features, but you do have to use the LCD screen on the back of the camera, which puts many of those cameras at a disadvantage when it comes to focusing. And so, take a look for these features, if you think these will be useful in your type of photography.

Class Description

Our Camera Buyer's guide will be your guide to figuring out the best digital camera for your needs.

Gear expert John Greengo dives into the major brands and lenses that are currently on the market.

John breaks down some of the more confusing aspects of mirrorless and DSLR's from focusing systems to sensor size; you'll get a better understanding of what the gear does so you can make an informed decision.

At the end of the class, John gives his recommendations for different types of photographers from the aspiring student to the filmmaker and everyone in between. If you're looking to purchase a camera or gift one to a budding photographer in your life- this free course will be your guide in making the best purchase.

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Denise Watson

Another outstanding class by John Greengo, my favorite Creative Live instructor. John's delivery is entertaining and his info clear and very easy to understand. If you need more explanation, well, don't worry - he's got a slide or PDF for that! I'm a working photographer and I learn something new with each of John's classes. Don't hesitate to buy any of his classes - you won't regret it.

David Reichel

Yes - there is such a thing as a free lunch - this class is it! I enjoy landscape, seascape, architecture, portrait and travel photography. I've been a Canon user for decades (film and then digital full frame with the 5D Mark II then 5D Mark IV). Recently I got a Fujifilm mirrorless medium format GFX 50R and discovered some Fujifilm features (e.g., film simulation, menu system) that resonate with me. I now have over-kill on full frame format and because I like the Fujifilm so much, I've been thinking about moving from my Canon 5D Mark IV to a Fujifilm X-T3 as my walk-around camera. This class helped me better understand the trade-offs and alleviated my concerns about a crop format sensor in the X-T3. On top of that, this is a great refresher course on camera fundamentals.

Sherry Throughmyeyes Prater

There a thousands of reviews/guides/ floating around the internet, but this one is by far the best by far. I usually watch a portion and then move on because I simply lose interest, but I watched every single lesson. John gives a very unbiased explanation of cameras, functions for every type of shooter. Not only would I recommend it, but I am going to recommend. I am a member of multiple photography groups on FB and one of the most asked questions is camera buying advice. This is excellent!