This tutorial aims to explain auto-focus points. Auto-focus points are the black boxes with a circle in that you see when you look down your viewfinder. The circle flashes red when focus is obtained at that point.
The best pictures have an interesting point within them for the eye to rest on. Somewhat confusingly this is called the 'point of focus' All good pictures have one, without it they become a boring shot that fails to draw the viewer in. The rest of this page will be about the camera's auto-focus points, not about composition and the 'point of focus'
Most of the older EOS cameras have five auto-focus points, but the newer ones now have nine. Knowing which focus points to use and when comes with practice.
Press the auto-focus point selection button () on the top right corner of the camera.
Use the directional arrows to select the desired point.(N.B. Pressing the 'Set' button will toggle between auto-selection and the center point).
I find that I mostly have my focus points set to auto-selection. The auto-selection feature works very well, but there are times when it gets it wrong. The camera more or less tends to focus on the nearest point in the frame. This can be problematic when you are trying to focus on a subject that is in some way framed by an object closer to the camera.
The picture above illustrates this problem. The camera has auto focused on the near objects resulting in the subject of the shot to be out of focus. I resolved this by manually setting the auto-focus to the center point:
The composure of these two images is exactly the same, the only difference is where the center of focus is. With the focus on the background the viewer is drawn into the image creating an all together more pleasing result.
If auto focus fails there is always manual focusing. Getting a correct and sharp focus manually is very difficult. I would only recommend using it as a last resort. Using the switch on the side of your lens change it from 'AF' to 'MF' Rotate the focusing ring until you obtain focus.
Have you ever tried to shoot a subject behind glass, but only been able to focus on the glass, not the subject? This is where manual focus can be useful. Set your lens to manual focus and shoot away! Sometimes once you have focused manually you can switch back to AF and the camera will be able to auto-focus on the subject. Sometimes...
The pictures above demonstrate the usefulness of manual focus. The camera desperately wanted to auto-focus on the glass, not the baby lobster. I switched the lens over to MF, and focused in as best as I could on the subject. I then switched back to auto-focus and the camera got a focus lock no problem. Despite the lobster being in focus the result was very poor. Shooting subjects behind glass is fraught with problems. Always avoid it if possible!
If your camera is having difficulty finding focus use the center point; this one is the best at obtaining focus.
If your camera's center focus point is a cross then this focus point is faster at focusing that the rest; useful for moving subjects.
If you are shooting lots of portrait shots you may find that you wish to set the focus point manually to one of the side 1/3 focus points for better composition.
Use AI Servo mode for shooting moving subjects.