Q. Which focus points do you tend to use the most often? Do you set a particular focus point and use that for a whole session, or switch focus points frequently?
GREAT question! I most often use ‘AF point expansion’ and change the zones continuously using the quick button available on the 7D (see the end of this post for more about that).
Focus is really the most confusing thing I’ve had to learn about my camera. There are SO many factors to achieving perfect focus and this can get really confusing. Lens quality, camera shake, motion blur, focus points, MF, AF, AI SERVO, One Shot AF. All of these can be highly confusing for new camera users. All of what Im about to explain is using my knowledge of the Canon 7D but the principles are the same for most other cameras that have the abilities of the 7D.
Auto Focus Mode //
Ok so first I’m going to explain the different modes available when you’re shooting in manual.
The screen on the top of the camera looks like this:
If you press the button on the top, that makes all the other numbers on the screen disappear and leaves the DRIVE speed lit and the FOCUS MODES lit. You use one turning wheel (the small one) to adjust one and the bigger wheel to adjust the other. Since I mentioned it, the different ‘drive’ modes determine if you do one click shooting, high speed continuous (holding the shutter button down and shooting up to 8 images per second) or slow speed continuous. Ok so the focus modes. ‘One Shot’ (as seen on the screen above) is good for non-moving or slow moving subjects. You press the shutter halfway down to focus and then the rest of the way down to shoot. The next option as you turn the wheel is called AI Servo. AI stands for ‘Artificial Intelligence’ and this mode uses mathematical algorithms to predict the movement of the subject you’re tracking. I always have my camera in this mode because I’m usually chasing kids around. While holding the shutter halfway down and tracking a moving subject, you’ll see the little focus point squares jumping around allover the screen as the focus continually changes. Press the shutter down the rest of the way when you’re ready to take the shot.
Focus Points //
Now to the original question about focus points. When you’re shooting in Full Auto, your camera will be using all of the available focus points to auto focus your shot. This can make for wonderfully sharp photos, but you lose all control over what is and isn’t in focus. If you manually select your manual focus point or select which auto focus points to use, you have more control over your image. The first step to accessing this part of your manual settings is to view your screen like this and toggle to the arrowed area:
When you click this box, you are presented with 5 different focus point options. The first is ‘Manual Selec.: Spot Auto Focus’:
In this mode (see the photo left) you use the small and larger turning wheel to move the focus point around on the screen. Then when you are shooting through the viewfinder, you will see a little box in the chosen location. You can then be sure that whatever that spot is focused on is what will be sharp as a tack. This mode is useful for adults who aren’t running around, portraits where you want to be sure that the focus is on the eye or whatnot. Also useful for product photography or photographing the same thing over and over. For photographers like me, I would be most likely to use this for those baby head shots, sharp as a tack newborn shots of the feet with everything else out of focus, etc. And if you’re a strictly 1/3rds guy or gal, you can set your spot to accommodate for that. This mode isn’t useful when you don’t have control over what you’re photographing because there’s no telling where your subject will be from one moment to the next. If you are a total control freak and HAVE to know what spot is in focus AND you have lightening fast manual settings skills, you can constantly change your focus point.
The second mode is called ‘Manual Selec: Single Point Auto Focus’. This works exactly the same as the above explanation for the first mode which is similarly named. The difference is that Single Point AF has a slightly larger area of focus. So where the above mode (SPOT point AF) can produce pin-sharp results, it can be very hard to maintain focus between pressing the shutter half-way and all the way. Use this Single Point mode if you want to manually select your focus point but have a bit of an easier time achieving it. See the first mode explained above to see how Single Point AF mode is useful. Please note that focus points can be changed mid-shooting. See the end of this post for how to do that.
The third mode is called ‘Manual Selec: AF point Expansion’. Manual AF point expansion is such a useful mode. It allows you to manually choose any one AF point to be the primary focus, but also makes additional surrounding points active, useful for sports photography and other moving subjects. This means that you can focus on the middle of a portrait subject’s face while also knowing that the area around is also focused. In this mode, you do still need to use the wheels to choose where the points of focus will be placed.
The fourth mode is called ‘Manual Select: Zone Auto Focus‘: This Zone AF mode is only available on the 7D. It allows you to select a cluster of focus points (middle, left, right, upper, lower). This is a great option for most types of photography and is great for a beginner who is concerned about poorly focusing an important shot.
The fifth and last option is called ‘Auto Select: 19 point AF’. This is the mode used by the camera when in full auto, although as we see here, it’s also available to us when shooting in manual. This allows the camera to use any of the available 19 focus points to focus on what IT thinks is the subject you’re photographing. This can be tricky for more creative photographers and I wouldn’t recommend using it if you want to have total control over your images.
Some stuff I think you should know //
Regardless of your type of camera, if you know your settings and your camera’s inner brain pretty well, you should be able to find most of the options I’ve spoken about within your camera’s settings menus.
But here are a few cool things I’ve discovered about focus points and the Canon 7D.
Changing your focus points while shooting
While you are shooting through the viewfinder, you can move the focus points you’re using without going into the menu. You very simply press this button and then move the focus point around with your turning wheels. Easy!
Checking your focus after you take the shot
In the main menus, there’s an option to display a red square on the main point of focus when viewing your images on your camera’s screen. This way, I can take a shot and quickly look down to be sure that the focus is where I wanted it. You can access this by selecting menu –> navigate to the second blue icon —> AF point display –> enable. Again, this makes a red square display at the main point(s) of focus when viewing the image on the camera’s screen.
Please use the comments below to ask any questions on this topic and I hope this has been helpful!