What makes or breaks a great shot? You have all the necessary elements to create that perfect photograph. The light is impeccable, your subject is ready, your composition is picture-perfect. You click with confidence and then notice later that your focus is off. How frustrating! What happened?
You must master your camera’s focus modes if you want to have those impeccably sharp images with flawless focus every time. If there’s one thing that you can’t “fix” in an editing software it’s a badly focused photograph.
What Is Camera Focus?
Camera focus is achieved when the lens elements converge the light from your subject perfectly onto the camera’s sensor. This convergence of light is achieved by moving the glass elements within your lens.
Autofocus (AF): camera’s focus sensor monitors the convergence of light at the sensor. If a perfect convergence is not achieved, it then moves the glass elements to achieve a perfect convergence. This is called autofocus.
Manual focus (MF): In manual focus, you move the glass elements by hand to achieve light convergence on the image sensor. Almost all autofocus lenses can be manually focused. However, you should first turn off the autofocus switch on your lens so as not to damage the AF motor while manually focusing the lens.
Camera Focus Modes
We all want those great sharp images that we can be proud of. Let’s take a look at different focus modes that your camera offers and when to use them.
1. One Shot Focus Mode
One Shot Focus–called AF in Canon and AF-S in Nikon–is the perfect mode when you are shooting subjects that are not moving.
This focus mode is usually activated when you half-press the shutter button. Most cameras by default make a beeping noise and flash the view finder’s focus point in red once the focus is achieved. The camera will lock the focus as long as you keep half-pressing the shutter button.
One Shot focus mode saves camera battery life compare to other autofocus modes.
When to use it? Any kind of still subjects such as; portrait photography of adults, still objects, or landscape photography.
Pro tip: The Autofocus Illuminator (also called AF assist) of your external flash only works with One Shot focus mode. This is especially helpful to know if you are doing low light photography with an external flash. Autofocus Illuminator is an infrared grid that is projected by your external flash to help camera with AF.
2. Continuous Focus Mode (AI Servo/AF-C)
Continuous Focus mode (called AI Servo in Canon, AF-C in Nikon) tracks moving objects and attempts to continuously keep the focus on your moving subjects. This focus mode is helpful when you are photographing moving objects. It works by predicting where your subject will be at a given time. It works for both slow and fast moving subjects (trains, cars) or even subjects that are changing direction while on the move (sports players, or a child running around).
Disadvantage: This focus mode continuously runs your focus motor and use more battery power than One Shot focus mode.
When to use it? Sporting events, moving objects (air shows, cars), Portrait photography when the subject is moving.
Pro tip: Select the continuous shooting mode when you are shooting moving objects. This way you can take a series of shots while the camera’s continuous focus track your subject’s movements.
3. AI Focus Mode
This focus mode is available only in Canon models. It is a combination of One Shot autofocus mode and the AI Servo (continuous autofocus mode). It behaves similarly to One Shot focus as long as your subject is not moving. However, if the subject starts moving, it will attempt to refocus. You will still hear the autofocus confirmation beep (when you half-press the shutter) but that does not mean the camera has locked your focus.
Disadvantage: In AI Focus mode you can not focus and recompose. This is because the camera will attempt to focus again while you are recomposing.
When to use it? If you suspect that your still subjects will suddenly move (almost never?)
Pro tip: We recommend that you stick to AI Servo (for subjects that move) or One Shot (for subjects that are still). The only use of this autofocus mode seems to be if you suspect your still subject will suddenly move. Which is rare.
4. Manual Focus
As the name implies, this focus mode involves manually moving the focus ring of your lens to achieve perfect focus. With the advent of Autofocus lenses and cameras, this mode is not used very much anymore except in very low light situations, macro photography, or for creative purposes.
Disadvantage: It takes time and effort when you have to manipulate the lens by hand to focus on your subject. You may even end up losing your shot because of the wasted time fiddling with the manual focus.
When to use it? Use manual focus when the light is not adequate enough for the autofocus to function properly or when you want to do creative projects and play with blur. It’s also recommended to use manual focus when doing macro photography and want to be absolutely precise about where the focus should be on your subject.
Pro tip: Try to switch to manual focus when doing Action or Sports shots. Pre-focus where you think your fast moving object will move and then shoot it as it comes into that spot. You need to be very quick and attentive when using manual focus this way, but you may end up with better shots then if you relied solely on the continuous focus mode.
6. Focus Modes in Live View
The Live View function lets you compose and focus your shots from the LCD screen on your camera. Some screens can flip and rotate so you can use them for self-portraits or for shooting at angles that are impossible to look through the viewfinder.
Note: Focusing in Live View mode is slower than through the viewfinder so this may not be ideal if you need a faster response time.
Live View Focus Modes in Nikon
- AF-S (single-servo autofocus): This is similar to One Shot focus mode. Half-pressing the shutter button focus on the subject that is in the selected focus area. Once the focus is achieved, it will stay locked as long as you keep the shutter button half pressed. If the distance between the camera and subject changes, you must re-focus.
- AF-F (full-time servo autofocus): AF-F focus mode will continuously attempt to focus on the subject that is located in the selected focus area. This focus mode is useful when doing movie recordings. The focus will be locked when you half-press the shutter button.
Live View Focus Modes in Canon
- Live Mode: In this mode, the camera will display a focus area rectangle on your LCD screen.
- Move this focus area to where you want the focus to be in.
- Then half-press the shutter to achieve focus.
- If the focus is achieved the focus area rectangle will turn green, if not it will turn red.
- As long as you keep the shutter button half-pressed after the focus is achieved, the focus will stay locked. You can focus and recompose as needed.
- Live Mode with Face Detection: In this mode, the camera automatically detects faces and focus on them.
- Quick Mode: When you use Quick Mode in Live View, the camera will use the dedicated AF sensor to focus (just like in viewfinder mode). This means that the Live View mode will disappear momentarily when you half-press the shutter button (More info) to achieve focus. Once, the focus is achieved you will hear a beep and the Live View will resume.
Some Sony cameras have Eye-AF mode. In this mode, the camera detects eyes and automatically focus on the nearest eye even if the subject move. This is a great feature if you are doing portrait photography where your model is constantly changing poses but you want the focus to remain on their eyes.
Tips on Camera Focus
1. Focus and Recompose
When you want to focus on an object and recompose your shot, you should first grab focus from your subject and lock it by keeping the shutter button half pressed. Then you are free to move the camera to recompose your shot. The focus will remain on the subject even if the focus point is no longer on the subject (due to recomposing). Here’s how to do it:
Steps to Focus and Recompose:
- Press the shutter halfway and achieve focus on the subject.
- While still pressing the shutter halfway, move the camera to achieve the desired composition
- Press the shutter button all the way to take the shot.
This is very useful when using different composition rules since it allows your subject to remain in focus while you move the camera.
2. Use the Back Button Focus
Back button focus is very useful in situations where you do not want to refocus every time you press the shutter button.
For example, if the distance between you and the subject is not changing, it can be a hassle when the camera re-focus every time you press the shutter button. By switching the focus mechanism to “back button” you can separate focus and shutter mechanism. By doing so, you are free to take shots without having to repeatedly grab focus from your subject.
Read our back button focus guide for more info.
Go Out and Get Those Sharp Images
Focus modes are there to help you achieve the sharpest images possible. Practice different modes in a variety of situations and get to know how the focus modes function.
Show us your progress by uploading some of your sharpest photos in the comments section and tell us how you achieved it.
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