Which Autofocus Mode should you use? Photography for Beginners Series
Out of focus images are such a common problem amongst beginners. I know how frustrating it is to find that what could have been a great photograph is actually out of focus! Sometimes it can be as simple as having your camera set to the wrong autofocus mode. Let me outline for you in this episode what these are and which autofocus mode to use.
Below is what is covered in Episode 9 (but it’s better and much more detailed on the podcast ;-))
So many beginners tell me they have problems with out of focus subjects even when they think their shutter speed was fast enough. I am going to help you set your camera up in a way that will allow you to achieve a sharp subject most of the time.
So let’s get started with auto focus modes. Just as there are different metering modes there are also different auto focus modes. Yes really! Your camera can focus for you in different ways. That is what we are going to talk about today.
Again, very frustratingly, the camera manufacturers all have variations on the names they give to these focusing modes. I am concentrating on Nikon and Canon here but if you are shooting with a different brand please don’t worry. Just look up auto focus or focus mode in your manual and you will see the names assigned to yours. Alternatively you can check out one of these forums;
Before I talk about auto focus modes I am going to talk about the simple act of focusing on a subject before taking a photograph. To focus your camera all you need to do is press your shutter button halfway down. Your shutter button being the button you take a photograph with. You need to have quite a light touch to do this. At the beginning you will probably take lots of photographs accidentally because you are pressing the button too hard. Just lightly down is all it takes to focus.
Ok so let’s discuss these different auto focus modes, what they mean and when you should use them.
AF-S or One Shot – Single Autofocus Mode
First up, on Nikon, we have AF-S (which stands for Auto Focus – Single) or One Shot if you are using Canon. It might be that you have a switch on your actual camera body to change between these auto focus modes but for many of you, you will have to go into the camera menu using your screen and change them there. Again, just check your manual or use the web if you are struggling to find it.
When you are set to AF-S or One Shot when you press your shutter button halfway your camera will focus once. Sometimes a focus light will flash on or a focus beep can be heard. This means focus has been achieved and you can take the photograph. In this mode, if focus can’t be achieved your camera won’t actually let you take a photograph.
However, let’s say you have pressed the shutter button halfway down and your camera has focused on your subject. Let’s also say your subject is a toddler. If that wriggly little toddler moves in between you pressing the shutter button half way and then pressing it all the way down to take the photograph then you will have missed focus!
When you are in AF-S or One Shot mode your camera and lens will focus once when you lightly press that shutter button. So you have to then take that photograph before your subject moves or you will have to focus all over again.
Obviously this isn’t much of a problem if you are taking photographs of stationary subjects. If there is no chance of anything moving then this auto focus mode will work perfectly for you.
AF-C or AI Servo – Continuous Autofocus Mode
Moving on to the next auto focus mode you have available to you and that is AF-C for Nikon users. This stands for Auto Focus – Continuous. For canon users this will be called AI Servo which stands for Artificial Intelligence. Servo just refers to the auto focusing mechanism.
AF-C or AI Servo is used for focusing on moving subjects. So let’s say you are photographing a toddler running towards you down a path. You would aim your focal point at the toddler’s face and you would lightly press your shutter button halfway down to focus. In this focus mode your camera will continuously refocus on your toddler’s face as they move towards you. But it will only do this for you as long as you keep that shutter button pressed halfway down and as long as you keep your camera trained on them. As soon as you lift your finger or move your camera suddenly then you have to start all over again.
AF-A or AI Focus – Automatic Autofocus Mode
Most of your cameras will have a third option which is AF-A which stands for Auto. Or for canon users AI Focus which again stands for Artificial Intelligence. When you are in this mode your camera will try to do some guess work for you. It will detect whether your subject is moving or stationary and it will switch between single or continuous focus depending on what is happening in your scene. This is actually the mode that is designed for beginners because you don’t have to remember to change your autofocus mode all the time depending on what you are shooting. The problem is – your camera will get this wrong sometimes!
I am all about giving you control so I am definitely not going to recommend you use this third option.
You don’t need your camera to guess for you. I am going to recommend that you select the autofocus mode that suits what you want to shoot. So if you are shooting stationary subjects – stick with AF-S or One Shot. If you shoot moving subjects – stick with AF-C or AI Servo.
What if your subjects are both still and moving? Well that is the story of my life! I photograph my subjects being still and then get them to move around all in the space of a minute or so. I also photograph kids – need I say more?! What I do is I keep my camera in AF-C mode almost all the time. Why? Because in that mode I can capture both still and moving subjects and achieve sharpness. Whereas in AF-S or One Shot mode – I will have a hard time focusing on moving subjects.
I am going to give you an example. I went out for a walk with the family recently and I took my camera along with me. On the course of that walk I took loads of photographs. Every now and then I would spy a spot that I wanted to pose the kids in. For these I would ask them to be still so I could get the shot I wanted. However, for the most part, I just captured what they were doing. Whether that was stirring puddle water with their sticks, running full speed along the path ahead of me, picking cherry blossoms and the rest. If I was a purist I would have switched between single and continuous focus depending on whether the kids were moving or not. But who actually remembers to do this every single time? And who can be bothered??? If you just stick to continuous focus then your camera will manage sharpness in any scenario whether your subject is moving or not. You just have to make sure that you keep your focal point trained on the subject and voila.
So why doesn’t everyone just keep their camera switched to continuous auto-focus all the time?
Well I will tell you. Different photographers have different techniques when it comes to focusing and one of those techniques will not work well with continuous auto-focus. However, it just so happens that I am going to help you to get to grips with a much more accurate and professional way of focusing on your subject (wherever they may be in the frame). That’s for next time though…
Before I finish up I am going to briefly touch on another auto-focusing option which is ‘Back Button Autofocus’. This is actually what I use to focus now but I certainly didn’t start using this method. I was introduced to it a couple of years ago and I have to say I do love it. It doesn’t quite belong in this beginner series but I have a podcast dedicated to back button focusing if you are interested in learning more about it and you can find it right here.
I will be back next time with more on focusing. It’s a pretty meaty subject and it is one that I get a lot of questions on. Seems to be a big issue for many of you beginners and I remember it was the one thing that used to frustrate me more than any other so I understand. That’s why I am fleshing this one out and chunking it up.
Next time we will be learning more about accurate focusing, particularly how you can focus on your subject wherever it is in your scene without focusing and recomposing. I hope you will join me!
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