# Question about BBF



## km78 (Nov 2, 2015)

I have started experimenting with BBF and am having an issue that I hope someone here can help with. I am practicing this technique on a figurine here in my living room and when I go to recompose and take the photo nothing happens (my camera will not take the photo). I am wondering if this is happening because the figurine is too small because when I use this technique on other things (vase of flowers, a basket, etc...) it works just fine. Does anyone know why this is happening? Thanks so much!!


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## Braineack (Nov 2, 2015)

did you change the shutter button from focus to release?


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## ronlane (Nov 2, 2015)

Are you holding the bbf down as you recompose?


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## km78 (Nov 2, 2015)

Braineack said:


> did you change the shutter button from focus to release?



I saw this mentioned on one tutorial I watched, however it was for a Canon and I could not find this on my camera...Nikon D3100. I am not really sure what it means or how to change it. Another tutorial I watched specifically for my camera body said to switch my camera to AF-ON which is what I did.


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## km78 (Nov 2, 2015)

ronlane said:


> Are you holding the bbf down as you recompose?



No, I only hold it down to focus then let go, recompose and try to take the photo. I did move the figurine to a different location and it worked then.


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## ronlane (Nov 2, 2015)

I always play it safe and just keep the button held. That way it doesn't try to refocus or anythign else.


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## Designer (Nov 2, 2015)

Besides; you've got your camera set to NOT take a photo if the subject is not in focus (or if there is not enough light).  

Change that setting.


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## km78 (Nov 2, 2015)

Designer said:


> Besides; you've got your camera set to NOT take a photo if the subject is not in focus (or if there is not enough light).
> 
> Change that setting.



How would I change this?


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## Braineack (Nov 2, 2015)

km78 said:


> Braineack said:
> 
> 
> > did you change the shutter button from focus to release?
> ...




The shutter button is still set to only fire if the focus has been acheived.  If you use set the AF-L button to AF ON, but fail to change the function of teh shutter button itself, it won't allow you to activate the shutter if when camera doesn't think the image is in focus (green dot).

seems like the D3100 can't disable the option.  Are you shooting in AF-C?  Try AF-S.  But this defeats the real benefit of BBF.

Or trying holding the shutter button down part way, BBF, recompose, then hit the shutter all the way.



This is just a simple firmware limitation that Nikon decided to exclude from the cheaper cameras for no reason.  Nikon likes to spend manhours removing code from firmware because why innovate when you can rest on laurels.


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## Designer (Nov 2, 2015)

Yes, that is simple enough that even *I* can do it that way.


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## dcbear78 (Nov 2, 2015)

km78 said:


> ronlane said:
> 
> 
> > Are you holding the bbf down as you recompose?
> ...



Here's a problem too. To really get the benefit of BBF you need to move your focus point around. So think of it to doing things backwards to the way you are now. Compose the shot, move the focus point to where you want it, hold down BBF and hit the shutter (whilst still holding the BBF). This also works best in AF-C which I imagine you are in ... maybe?


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## km78 (Nov 2, 2015)

ronlane said:


> I always play it safe and just keep the button held. That way it doesn't try to refocus or anythign else.



So you hold down


Braineack said:


> km78 said:
> 
> 
> > Braineack said:
> ...




Yes, I have my camera set to AF-C  but tried AF-S and it still doesn't work. I tried it the other way you mentioned and I must be doing something wrong because the photo is coming out way over exposed. Besides that, I am finding it difficult to press the shutter half way down while trying to press the BBF button at the same time. I am sure this takes practice but is it worth it to shoot this way rather than the focus and recompose method since my camera is cheaper and will not allow me to do it the right way?


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## dcbear78 (Nov 2, 2015)

You don't have to half press the shutter if using BBF.


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## km78 (Nov 2, 2015)

dcbear78 said:


> km78 said:
> 
> 
> > ronlane said:
> ...



Okay now I am really confused because I though that one of the benefits of using BBF is so that you would not have to worry about moving the focus points. Right now, I have my focus point set on the middle. I focus on my subject using that middle focus point, press the BFF button and then recompose. I obviously need to learn about BFF some more, but now I am starting to think that I should just forget it altogether now that I know that my camera will not allow me to shoot this way.


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## Braineack (Nov 2, 2015)

dcbear78 said:


> You don't have to half press the shutter if using BBF.



true on most cameras,  but Nikon decided to strip out the ability to change the shutter to "release"  on the D3100.  Because they decided that entry-level cameras should also have entry-level features -- instead of just leaving in the code and marketing the robust feature set of even entry-level cameras.

So yeah, you can change the BB to "AF ON"  but the shutter button itself is still going to wait for focus.  So if you hold the BBF, then recompose and try to fire, it's not going to work (itll probably just try to focus again).


Using AF-Lock might work better for your needs.  you can focus, hit AF-Lock, then recompose and shoot.  But the use BBF as it should be used with AF ON doesnt seem to be an option for D3100 owners.



km78 said:


> ...and I must be doing something wrong because the photo is coming out way over exposed...



Metering has changed.


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## Designer (Nov 2, 2015)

km78 said:


> I am finding it difficult to press the shutter half way down while trying to press the BBF button at the same time.


I wouldn't think that you need to do both, as either one should perform the function that you want. 

Maybe just go back to the old way of shutter button half way, recompose, and finish the press.

There's one possible problem, however; and that is if your DOF is thin, and what you focused on was somewhat behind or in front of your desired focal point, then you're going to end up with a blurred point of focus.  (such as the eyes, for instance)  So keep the DOF at a thickness that will include both the point of focus and your subject's eyes.  Or if you know the point of focus (for the camera) is at the same distance as from your subject's eyes, then your DOF can be as thin as you want.


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## km78 (Nov 2, 2015)

Okay, so here is a question that I have now that I know that my D3100 will not allow me to shoot exactly the way that BFF was intended...

Should I continue to shoot the way I have been which is moving the focus point and half pressing the shutter to lock focus or moving the focus point and using the BFF button to lock focus? Would that basically produce the same results as far as sharpness or is one method better than the other?


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## Derrel (Nov 2, 2015)

Keeping the focusing initiation on the shutter release button, and setting the thumb button to lock focus _as long as the button is held down_ is the way I would do it.

What is complicated on the issue is the specific camera models can have different options, different ways to configure the button; some cameras have two buttons!

An example: does the lock feature lock both the focus AND the metering, or does it lock focus, but allow the meter to run free? This is a real issue at times, and can be configured differently, based on the camera in use. Braineack's comments seem to suggest that the D3100 works somewhat differently from some other Nikons.

There is no one, single best way to configure a camera for back button focusing; in fact, it might be better not to use it at all in many situations; AF-S can be an easy substitute in many situations.


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## Braineack (Nov 2, 2015)

Derrel said:


> Braineack's comments seem to suggest that the D3100 works somewhat differently from some other Nikons.


yeah, if you google BBF and D3100 problems  you'll find plenty of people complaining about it.  I think I remember having the same complaint long ago when I tried it when I still had a D3100.


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## wfooshee (Nov 2, 2015)

Just going back to the original premise of achieving focus, you want to try to avoid moving the camera after composing for two reasons.

1. Moving the camera changes lens to subject distance, which blows critical focus. Centering the lens on the focus point, focusing, then composing does NOT give the same result as composing, selecting a focus sensor over your desired point, and _then_ focusing.

2. if you move the camera with the shutter button half-pressed, you've engaged AE-lock (with the default settings) so you've metered on a composition different from what you're shooting. 

And as already pointed out, you're running against the limitations of the "consumer-grade" electronics of the camera. All the discussion of whether you're in AF-S or AF-C _should_ be irrelevant when using BBF; set the camera to AF-C, but for single AF, hit and release the back button, and for continuous AF, just hold the button. Couldn't be easier to switch between modes! For that to work, though, you have to be able to shoot without focus confirmation, i.e. release priority instead of focus priority, which apparently the D3100 is not capable of doing.

I'm thinking you ought to go back to the default shutter button behavior, simply because although the camera lets you set the back button to AF-ON, it doesn't quite behave as real BBF ought to.


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## km78 (Nov 4, 2015)

I will continue to experiment to find which way works best for me. I really appreciate the help and advice I have received. 

Just curious though...What is everyone's preferred method of shooting with regards to BBF, etc...?

Thanks so much!


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## dcbear78 (Nov 5, 2015)

I was unaware of these issues with this model. I learned on Pentax's that do not unnecessarily cripple features unless it is a hardware limitation.

So knowing it's limitations and that it can't be used the way I like to use BBF I'd suggest not. Seems like it would actually be more difficult.


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## charchri4 (Nov 5, 2015)

Sorry to be a total noob but google came up with 23 definitions of BBF so could you decode what you're talking about for me?


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## JacaRanda (Nov 5, 2015)

charchri4 said:


> Sorry to be a total noob but google came up with 23 definitions of BBF so could you decode what you're talking about for me?



Back Button Focus: What is it and why should you try it? 

IMO it's more useful for moving subjects, or static subjects that may move.  Example - a wading bird moving around in a pond that you can continuously track and focus (ai servo on canon) using bbf.  When it's not moving, let go of the back button, when it starts to move, hold down the back button; even if it takes flight.  Push the shutter button any time while either holding the bb down or not.

3 Reasons Why You Should Switch To Back Button Focus





I don't see any reason to turn it on and off like he suggests.  But whatever works for you.


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## charchri4 (Nov 5, 2015)

LOL that is too funny!  I just read about that last night in Tony Northrups book and set my K-3 up to do that!  The first few shots I'm not seeing any advantage what so ever but I'm going to try it for a while.


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## JacaRanda (Nov 5, 2015)

charchri4 said:


> LOL that is too funny!  I just read about that last night in Tony Northrups book and set my K-3 up to do that!  The first few shots I'm not seeing any advantage what so ever but I'm going to try it for a while.



I switched the video because the second one does a better job explaining it's use imo.


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## Braineack (Nov 5, 2015)

charchri4 said:


> The first few shots I'm not seeing any advantage what so ever but I'm going to try it for a while.



This is like writing a few lines text on a legal sheet of paper and saying I don't see the advantage of the extra 3".


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## JacaRanda (Nov 5, 2015)

Braineack said:


> charchri4 said:
> 
> 
> > The first few shots I'm not seeing any advantage what so ever but I'm going to try it for a while.
> ...



For some reason, it's seems that some people make it more difficult than it really is; when it's just another tool.  Use it if it works for you, or don't.  But to judge it before ever using it (for a few shots)...Oh well.

You meaning anyone, not you as in Braineack.  I think you have found it useful at this point.


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## charchri4 (Nov 5, 2015)

This is Tony's explanation and he shows why it works better very clearly.  




But it is really awkward and the AF button on the K-3 is about a 1/4 too high on the body to be perfect for my hand.  I've forgotten to focus a couple times but we'll see how it goes.  

Thanks for a great thread!


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## Braineack (Nov 5, 2015)

JacaRanda said:


> You meaning anyone, not you as in Braineack.  I think you have found it useful at this point.


I use it all the time now.  I only turn it off if I hand the camera to someone.


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## charchri4 (Nov 5, 2015)

Braineack said:


> charchri4 said:
> 
> 
> > The first few shots I'm not seeing any advantage what so ever but I'm going to try it for a while.
> ...



Oh I quite agree and have a long way to go before I would give up on it.  I've only shot about 10 shots with it messing around and I was playing with a manual focus prime at the same time so lots of distractions.


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## JacaRanda (Nov 5, 2015)

charchri4 said:


> This is Tony's explanation and he shows why it works better very clearly.
> 
> 
> 
> ...


Right, that's the video I posted first.  I just think the second one explained it better.  Lots will depend on how your cameras ergonomics are setup.


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## charchri4 (Nov 5, 2015)

Ahh I didn't catch the first video before the change.  Good point on the race car prefocus.   What you say makes a lot of sense that once you have it set that way I wouldn't change it because if you handed your camera to someone you would put it in green mode anyway.


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## Braineack (Nov 5, 2015)

charchri4 said:


> if you handed your camera to someone you would put it in green mode anyway.



now youre just talking crazy


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## charchri4 (Nov 5, 2015)

LOL yeah I thought that as I wrote that.  Who would I feel comfortable handing my camera to?  Well maybe one of you guys but no one I know in the real world!


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## Braineack (Nov 5, 2015)

setup the camera, then hand it over.


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## Dave442 (Nov 5, 2015)

I am using BBF in the following way:
- Autofocus is set to AF-ON only (the BBF setting).
- Set to AF-C unless I want to make use of the focus-assist of a speedlight where I go to AF-S. 
- In the menu I have AF-C set to Release priority and AF-S is set to Focus priority. 
- I select a focus point and if the subject is moving then I keep the subject in the active focus area and keep AF-ON pressed, if subject is still then I usually push and release the AF-ON various times finding the focus I want and then recompose if desired and take the shot. 

BTW - my wife and grandson learned BBF; just like you hand the camera to someone and tell what the shutter button is, you also tell them the button to focus.  Of course I handed the camera to my sister and she just manually focused, as is her preference, and BBF is perfect for doing that as well.


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## JacaRanda (Nov 5, 2015)

Dave442 said:


> BTW - my wife and grandson learned BBF; just like you hand the camera to someone and tell what the shutter button is, you also tell them the button to focus.



Same here.  I've done it several times.  They ask how many mm is the lens or say "I bet you can see real far with that thing" or "Wow, that's some camera".  That's when I let them feel how heavy the rig is and then hand it over so they can check it out.  Here is the button to focus....piece of cake.


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## charchri4 (Nov 6, 2015)

Dave442 said:


> I am using BBF in the following way:
> 
> - In the menu I have AF-C set to Release priority and AF-S is set to Focus priority.



Can you expand on these settings?  I don't understand the difference between release priority and focus priority and when to use what for what.


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## Braineack (Nov 6, 2015)

release prioirty means it will take the picture anytime you push the button.
focus priorirty means it will only take a picture if you're in focus.


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## Designer (Nov 6, 2015)

charchri4 said:


> Dave442 said:
> 
> 
> > I am using BBF in the following way:
> ...


"Release priority" means when you release the shutter, (press the button) it will release the shutter regardless of where the focus (for instance) is.  "Focus priority" means the shutter does not release until and unless the image (the spot you have chosen) is in focus.


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## charchri4 (Nov 6, 2015)

Thank YOU!  After I posted that I looked in my camera manual and read the same.  I had set mine to focus thinking there would never be a time when I would want what would have been a good shot if it was in focus anyway.  But if you are in AF-C I suppose it would not be an issue.  Fascinating myriad of technical stuff in these little black boxes!


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## charchri4 (Nov 6, 2015)

LOL Yep forgot to push the button!


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