# does my camera do bbf?



## paigew (Jun 28, 2012)

I have the rebel t3i and I have been trying to figure out if it has back button focus. I didn't see anything in the manual about it. Does anyone know if it can do it?


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## KmH (Jun 28, 2012)

You should be able configure your T31 for back button focus. The information would be in the user's manual.

It's usually related to the AE/AF lock button on the back of the camera.

http://www.google.com/search?rlz=1C...rceid=chrome&ie=UTF-8&q=T3i+back+button+focus


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## sovietdoc (Jun 28, 2012)

oh that's what bbf means.  I was thinking of something completely different.


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## 2WheelPhoto (Jun 28, 2012)

My cam does BFF's too


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## o hey tyler (Jun 28, 2012)

Paige. Look in the custom functions... I would tell you what the custom function is, and what it needs to be set to, but I don't have my camera in front of me.


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## Big Mike (Jun 28, 2012)

On my older Canons, it was Custom Function #4, but I'd think the T3i has a newer menu system than that.  Just check the manual under Custom Functions and/or the AEL (*) button.


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## pixmedic (Jun 28, 2012)

OMG...i read the title too fast and thought you asked if your camera did BBW! 
Whoops.


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## paigew (Jun 28, 2012)

o hey tyler said:


> Paige. Look in the custom functions... I would tell you what the custom function is, and what it needs to be set to, but I don't have my camera in front of me.



Okay I found it!! Thanks! 

So now another question. When I use bbf my subject needs to stay in the same plane of focus right? They can't be moving towards or away from me because my focus will be locked right? I am a little confused as to when I would use this. It was suggested to me to use because when I shoot (al servo) the focus point light doesn't stay on (as it does with one shot) so sometimes I miss focus (because I can't tell where the dot is if it is really bright outside).


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## paigew (Jun 28, 2012)

okay sorry to be posting so much but am I understanding this right. I have been re reading the manual but it is so confusing and I am not good at deciphering all this technical stuff 

_af/af lock; no ae lock_: From what I understand, basically it is useful on a stationary subject so my af doesn't catch things. Example, yesterday I was taking pics of my kid playing in the water and the af kept catching on the water drops instead of him. So I could use bbf in a situation like this. 

_AE/AF, no ae lock_: useful for subjects moving and stopping repeatedly. Isn't this the same as using al servo without bbf?


Not really sure why it was recommended to me for the reason I listed  above (keeping light on) because my light doesn't stay on when I am  using it.


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## MTVision (Jun 28, 2012)

paigew said:
			
		

> okay sorry to be posting so much but am I understanding this right. I have been re reading the manual but it is so confusing and I am not good at deciphering all this technical stuff
> 
> af/af lock; no ae lock: From what I understand, basically it is useful on a stationary subject so my af doesn't catch things. Example, yesterday I was taking pics of my kid playing in the water and the af kept catching on the water drops instead of him. So I could use bbf in a situation like this.
> 
> ...



Honestly BBF isn't all that much different then regular focusing. You would just use that button to focus instead of the shutter button. 

If you use one shot focus mode then it locks focus when you hit the button. If its a stationary subject you can take multiple shots without having to refocus. 

I'm not sure if it's accurate but I've heard that in continuous (al servo) if you hold the back button down - you can track and it will keep focusing but when you let go of the button the focus is locked and you can recompose.


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## o hey tyler (Jun 28, 2012)

My 5DMK1 is set up to be AE/AF, No AE Lock. It's under Custom function 04 on this camera. 

My 5DMKII is set up to be AE Lock/Metering + AF Start. It's under C. Fn IV: Operation/Others. 

I also use ONLY the center point on both cameras and recompose my shots. I have AI-Servo as my focus mode 100% of the time. It's not as finicky as Nikon cameras where you seem to need to hold down the back button until the shutter actuates, basically constraining you to AF-S. Meaning you can't use a servo mode, or at least that's been my experience. 

If you are having difficulties, you can always reach me on FB or Skype. But I'm sure you knew that.


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## paigew (Jun 28, 2012)

yes you can hold it down and hear/see it focusing as the subject moves. It is what I use almost all the time. Thanks for clarifying I was thinking it (bbf) was some awesome technique the way I hear people talking about it. At least I know how to set it now


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## o hey tyler (Jun 28, 2012)

BBF is an awesome feature, and I recommend that everyone use it.


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## paigew (Jun 28, 2012)

thanks tyler for help. So, I'm a visual learner can you post a pic where you used the  AE Lock/Metering + AF Start mode? I am not really understand what is different about bbf and al servo. They both keep the subject in focus until you press shutter  

sorry my brain is kind of fried :blushing:


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## o hey tyler (Jun 28, 2012)

All BBF does is replace half pressing the shutter to focus with the AE Lock button on the back of the camera. That's the major difference. You can use AI Servo mode with BBF. It would be more helpful to post a video, or if you can skype I can show you over video chat.


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## Big Mike (Jun 29, 2012)

The way I use BBF, is so that I can use AI Servo, but also lock the focus when I want to focus and recompose (like it was in One Shot).

The problem with using shutter-button-focus and AI Servo, is that you can't focus and recompose...the camera will always focus when you press the button to take the photo.  By taking focus away from the shutter button (putting in on the back button) you can independently turn the focus on or off (turning it off is essentially locking it).

So sometimes, I'll be holding down the back button, which would be just like shutter-button-focus in AI Servo mode.  But rather than switch to One Shot focus mode, I just release the back button when I want to lock the focus.


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