Focus Points

maiMelissa

Hi all,
I have read about focus points, but I still have no clue as to how to use them or how they work. If I'm taking a picture of an object should all the focus points be on that object? Is it better to just leave the camera to determine the focus points? I guess my question is how do you determine where to put your focus points if you are taking a picture of a person? Please tell me how you use the focus points; I need tips. At the moment I just let the camera do it but I'm not understanding how they work. Please help.

PBked

Hi Melissa,
There are three ways to use the AF points. First, there is fully automatic where the camera selects one or more focus points. The problem with this is that the camera may choose the wrong points for your needs. For example, say you want to photograph a person standing between and behind two trees so your trees and person make a triangle. Using full auto AF may pick out one or both trees and not the person. So the tree is perfectly in focus and the person blurred!
The second way is to select the focus point yourself. You do this by pressing the AF button and then use the scroll wheel to move round the points. Say you wanted the right hand tree to be in focus and the person blurred then you would choose the point that will be focussing on the tree.
The third way is to use the center focus point only. The quick way to choose this is to press the AF button and then set. Doing this toggles you between center and auto. With only the center focus point active when doing a portrait you focus on the eyes and this makes sure that the person's whole face is in focus. Some people I know never use anything else but the center point, however, when you think it through, your autofocus is offering you nine different areas of focus to enhance creativity.
I'm a great one for suggesting experiments so if you have a tripod, try this. Set up a scene in your garden using what you have to hand (a flowerpot or two, a chair). Set your camera to AV and choose a fairly wide aperture, say f/3.5 or f/4. If you are using your 18-55mm make sure the IS is switched off on the lens while it is on the tripod. Now select each AF point in turn as explained above. When you review your pictures you should be able to see the differences.
Let me know how it worked out.
Regards,
PBked

PBked

Try this link for lots more information:
http://www.youtube.com/user/BHPhotoVideoProAudio/videos?query=Canon+Autofocus

MisterD

@PBked
That is some excellent advice! I never knew about manual selection of the focus point(s) and will definitely have a practice session to check out the results. Many thanks!

maiMelissa

Thanks PBKed, I will try that; although I don't have tripod yet!