Newbe Q about auto focus in 70D

[goingbananas]

Hi,

  I have always had a love for taking photos but, like many, never really knew the technical aspect of it all.

I want to learn everything I can. I have purchased a 70D and am reading much and trying to play around with it. It is going to take me a while to understand this and I know I am in for a lifetime of learning.  But here I am with a question that is probably going to make some squirm because I assume it is incredibly simple but I just cant figure it out (YET) hah

   Get ready, here it is! 

     This seems to be happening in both the auto mode and manual mode, I press the shutter button halfway, it focuses, i press all the way and nothing happens. There are no indicators that I am trying to do something really rediculous. I am in daylight shooting a flower. so I let go and try again, halfway it focuses, all the way nothing. Shouldnt I be able to tell the camera to take the picture, whether or not  IT wants to? blurry or not blurry? Then all of a sudden, I will try it again and it works.  

 It is one of those things where I am trying to do searches on google and instead I am getting results for who the hell knows what, so I figured I should just register here and ask, because I will more than likely be here a lot now.

  So i am asking here, please go easy on me.

( BTW the camera is brand new)

[ScottyP]

Camera is not able to autofocus, in this case probably because you were too close to the flower.

I applaud getting out of Auto mode, but I wouldn't go straight to Manual mode. Learn Av mode and TV mode, which lets you set one value (lens aperture size for Av or shutter speed for Tv) and the camera handles the other variables to give you a properly exposed image. In Manual you are entirely on your own and it is not good for beginners and there is probably no need for it in your shooting.

Good luck and have fun with your shooting and learning!

[TCampbell]

To focus, the camera needs:

1) Enough light - it can't focus in extreme dark

2) Enough contrast - it can't focus on things with no contrast (e.g. a plain blue sky)

3) A subject which is within the focus distance range of the lens (cannot be closer than the minimum focus distance.)

If you have all three, it should focus.

If the problem is inadequate light, then an external flash with focus-assist beam can help (e.g. the 430EX III-RT has a focus-assit beam which emits a red pattern that the camera can use to lock focus -- even in total darkness.)

If the camera is in "One-Shot" mode then it implies a feature called "Focus Priority". In that mode it will not take an exposure unless it can confirm that it has successfully locked focus on at least one focus point.

If the camera is in "AI-Servo" mode then it uses a feature called "Release Priority" and it WILL take an exposure as soon as you fully press the shutter button (and it will do this whether or not it was able to focus. This means you should use it with care or you may end up with out-of-focus images if the camera was not able to focus.)

If you switch the AF/MF switch on your lens to the manual focus (MF) position, the camera will always take an exposure as soon as you fully press the shutter button. In manual focus mode the camera will not attempt to focus (but iin some modes it will blink and/or beep as you manually focus the lens to tell you if it think YOU focused on your subject successfully. Regardless, it will always take the shot if you switch off auto-focus.)