It really does not matter if the rest of the settings on your camera are correct; your image will be completely ruined if it is out of focus. That means you need to understand focus completely, and that would include both manual focus and autofocus. When it comes to point and shoot cameras, focus is so easy and is completely handled for you. However, your DSLR camera is totally different. The focus is handled in a different way and understanding focus matters all the more. If you want to learn the very best in digital photography, then you must have a very strong understanding of focus.
The Basics of Autofocus
Of course, you will find that autofocus is most useful in many different situations. For beginners, auto focus is a must since learning the fine points of manually focusing can be overwhelming. For more experienced photographers, autofocus will simply be a convenience that allows the photographer to work with the exposure settings for the best picture. There are some things that you need to understand about autofocus in order for you to use it and your camera properly for the best digital photography.
A Few Things to Consider
Autofocus is not necessarily perfect. In fact, if you do not understand how it works, you could get very frustrated in a hurry. There are some things that you need to consider and understand about this mode so that you can know what to expect and so that you can use autofocus properly. Here are some things that you need to consider.
Your camera will not trigger autofocus until you partially depress the shutter release button. If you do not take this step, on most cameras, your camera will not be able to focus properly.
Different cameras have different autofocus speeds. No matter what, the focus will not happen instantaneously. You will need to be patient and allow the focusing mechanism to work properly. The reason for this has to do with the lens. Many people do not realize it, but the lens has a tiny motor within it that controls the autofocus. For example, it is fairly well known that Canon cameras and lenses make use of several different motors for a faster focus. Nikon, however, uses a more exact motor that will find the right focus in a better manner, but it will work slower.
Different cameras also have different sensor areas. The autofocus on a camera makes use of different points on the frame to find the focus. You will have control over which point on the frame is actually the focal point. At minimum, a DSLR camera will have three autofocus points. At this point, the maximum autofocus areas that you will find on a camera will be 51. In essence, the more autofocus points available, the more control you will have over where the image focuses.
The camera will not always work well with autofocus. For example, some situations, like shooting through glass, will confuse the autofocus. The autofocus in these situations will try to focus on the wrong thing, like the glass itself. You will want to switch to manual focus in order to get the image that is beyond the glass.
There are three main types of autofocus modes that any DSLR camera will have. You will need to learn what these three modes mean and then you will need to know how to use them properly so that you can control when your camera decides the focus. This will allow you to have more control over your digital photography, and it can actually eliminate a great deal of frustration. Here is more detail on the different autofocus modes.
AF-S (Single Autofocus)
This setting goes by different names, and they include single focus, single servo, and one shot autofocus. They all mean the same thing. With this setting, your camera will set the autofocus when you partially depress the shutter release. The focus will not change from then until when you take the image. This way, you will not have to worry about the focus changing once you have lined up the image.
AF-C (Continuous Autofocus)
Sometimes referred to as AI Servo, this autofocus method for digital photography is different. In this method, the camera will focus when you partially depress the shutter release, but it will continue tracking the image in the frame and it may actually change the focus when you actually take the image. This option is a good choice if your subject is moving.
AF-A (Automatic Autofocus)
This option is not yet available on all DSLR cameras, but it is definitely becoming more popular. With this mode, it is a combination of the two previously named. Your camera will determine the situation and can change between single and continuous autofocus depending on whether the subject is moving or not.
Switching to Manual
If you find yourself in a situation when autofocus is not ideal or when your camera just cannot focus the way that you want it, then you will need to learn how to make use of manual focus. Truthfully, manual focus will take some time and practice because it truly does require a trained eye. To get more used to manual focus, you will need to consider a few things.
You will need more time to take the picture. Manual focus will take much longer than autofocus as you get the image correct. You will need to make sure you have the time to focus and take the image. You will also need to make sure you have the patience.
You will have to learn to be accurate. When you try to use manual focus, you are in total control. That means you need to make sure you are focusing on the right subject and you cannot blame the camera if something is out of focus.
Learning how to properly use focus is an absolute must in digital photography. No matter what, you will want each of your images to be properly focused. Whether you use manual or autofocus, you will need to understand how the camera works for the best image possible.
Keep on shooting!
Top image by Nana B Agyei