# Back button focus



## SquarePeg (Mar 17, 2016)

Can someone explain the advantages/disadvantages or point me toward a good resource on back button focus? Using a 7100... 

specific questions

How to set it up?  
When/why to use it?
Is it just a more advanced process of focus/recompose?
Can you opt back and forth with standard focus on the fly? 

I'm sure I'll have more questions once I give it a try.  Thanks!


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## JacaRanda (Mar 17, 2016)

Here you go: Back Button Focus: What it is, why you want it & setup guide

Scroll down far enough and it shows some specifics for the D7000 (hope it's close enough).


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## SquarePeg (Mar 17, 2016)

JacaRanda said:


> Here you go: Back Button Focus: What it is, why you want it & setup guide
> 
> Scroll down far enough and it shows some specifics for the D7000 (hope it's close enough).



Great!!!  Thank you so much.


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## Overread (Mar 17, 2016)

SquarePeg said:


> How to set it up?



Varies from camera to camera and I can't say for your Nikon but should be easy to google that info or find it in the manual



> When/why to use it?


Honestly I'm hard pressed to think of situations where you don't want to use it unless you've got:
1) An older camera that doesn't have a dedicated back-button for the AF (some twinned it with the pre-flash fire button)

2) If you're handing the camera to someone who doesn't know how to use backbutton (although sometimes for those groups just clicking it into auto mode - which doesn't support back button AF - at least in Canon - can work).



> Is it just a more advanced process of focus/recompose?



No; in fact its not really anything to do with focus and recompose. Backbutton AF is about separating the act of metering and taking the photo from the act of focusing the photo. This means that with backbutton AF you can enable the metering (half press of the shutter) and take a shot (full press of the shutter) without the AF motors engaging at all.

This is powerful because it means that you can pre-focus and leave the focus fixed; focus and recompose; focus once and lock the focus etc... It also means you can take meter readings without the AF trying to do anything. 




> Can you opt back and forth with standard focus on the fly?



Yes and no and Yes.

Yes because, as said, if you enable auto-mode you get normal focusing back on the shutter button; but you also then have to deal with auto mode doing everything else too. 

No because you honestly won't need to. Once you get used to backbutton AF you likely won't go back; you can just shift the menu options back and forth as you need, but most find no need to do it. 

Yes because when you have a lens with full-time manual focusing you can shift into manual focusing without doing anything. You just turn the focusing ring and focus the lens whilst in AF mode on the lens; because the AF on the camera won't engage until the backbutton is pressed, so you just don't press it. And because its not on the shutter the act of taking the shot won't suddenly engage the AF for a split second to try and focus.

Of course any lens without fulltime manual focusing will have to have the AF switched changed (to allow the focusing wheel to move and affect focus); but otherwise this allows you to swap between auto and manual focusing on the fly without having to hunt over hte lens body to find the AF on/off switch.


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## 480sparky (Mar 17, 2016)

Overread said:


> ..........Honestly I'm hard pressed to think of situations where you don't want to use it ...........



I don't use it when I'm shooting fast action like sports or moving wildlife.  My D600s are set to BBF as I usually am shooting landscapes, architecture etc.  So BBF makes sense to me for that.

But my D7100/200-500/1.4TC Stack is not because that's what I use to shoot BIFs, sports etc.


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## NancyMoranG (Mar 17, 2016)

Peg, I am using it based on suggestions on TPF. I didn't even know the stuff overead posted (zheezs :{ )
But I think a lot of people in the Nature forum use it. SCraig and Jaca come to mind. You might wander over there...
Sorry I can't help much.


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## pjaye (Mar 17, 2016)

All of your questions were answered, but just wanted to add, I use it. Took a couple of days to get the hang of it, but I love it. I have a Nikon D7000 & D7100. I shoot mostly wildlife.


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## Derrel (Mar 17, 2016)

BBF is not a panacea. The biggest danger with it is forgetting to re-focus when you shoot quickly...it's easy to end up with multiple OOF images. Not every situation is best with the shutter actuation and the focusing step "segregated" into two, distinct operations. In situation s where you have a large, heavy lens, or when you have really shallow depth of field, or you are using the 4-way controller to move the AF point to start with, it really is dumb to use it, since it takes away your thumb as an actual TOOL to manipulate the camera. The second biggest danger is that it can VERY easily lead you into the habit of focus-once and never-refine, never-reset the focus over a sequence of shots.

How BBF is implemented depends too on the specific camera, and its control options. I've been shooting the pro Nikons for 15 years, and they have two buttons on the horizontal shooting mode: a separate AF-ON button, an a combination AE-L/AF-Lock button right next to one another. In vertical mode, there is just the AF ON button. There are several permutations on how the buttons actually function....AF os active when the button is held in? AF is active and then locks once the button is released. Light meter reading tied to the AF lock position, or light meter free to adjust but focus locked? etc.etc..

I seldom use back button focusing, but I do use the AF-Lock quite a bit. I know imagemaker46 does not use back-button focus, so it's not that one needs to use BBF, even to shoot action spots, or to be an accomplished shooter.

I personally think that linking the focusing operation to the trigger in AF-C, and having my right thumb free to move the AF point to the desired area trumps BBF.

It depends on how you want the camera to work...and how you want to use the AF system: wither with one AF point, or with a group AF point like 9-point, 11-point, or 21-point, or all 39 or all 51 points. I think for a lot of continuous action, BBF is misguided....for some things like baseball, where you might easily want to set the AF to a specific base and hold the camera on a monopod and wait for the play that you KNOW MUST be to a specific base under a specific base runner and pitch count or strategic situation, BBF can be handy.

Still, I prefer to have the camera in AF-Continuous and to RE-focus for each and EVERY frame, so to me BBF makes little sense for people work...it's just way,way too easy to set a focus and then leave it there. The higher the magapixels, the shallower the depth of field, the longer the focal length, the more *I want a NEW focus established for every single press of the trigger*, and I want it all done in one step...with the trigger.

I think BBF is often way over-touted on-line. it appeals to people who distrust their AF system, or who typically want to use it as if it's a one-AF-area camera, using just ONE, single frame of reference to focus, and they to stay with that one-point AF lock. I distrust that idea...I ant the focus to be NEW for each frame, and want to use my thumb to move the AF area at any and all times, and to have my THUMB free for gripping the camera and for moving the shutter speed wheel...

Part of this might also be body-dependent; on a camera with a weaker AF module, the focusing system is often not the best, and with a slower lens (say f/4.5~5.6), or with wide-angle lenses that have low magnification, I totally,totally,totally DISTRUST using one, single AF lock for more than one or two frames.


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## Overread (Mar 17, 2016)

I just leave backbutton focusing on and hold the button down for continual refocusing. 
Gives me the same grip on the camera; although I do back that up with a battery grip and wrist strap. 

That's when shooting anything; - landscapes, macro*, wildlife, showjumping, people etc....

To my mind the mode lets you do everything the shutter button AF does and more because the functions are split. To me it makes focusing easier. 

*Yes for macro. Because I don't use AF for macro it means that I can just put the lens on and shoot; and if I want to use AF for a further off shot I just press the button; no hunting for switches on the lens body. I only have to hunt for a switch on my 35mm because it hasn't got fulltime manual focusing.


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## Derrel (Mar 17, 2016)

JacaRanda said:
			
		

> Back Button Focus: What it is, why you want it & setup guide



Okay, let's take this fellow's first instance of why one would want to use BBF.

"*EXAMPLE NUMBER ONE*

First, suppose you are shooting *portraits*.  The person who you are shooting is standing still and you want to take several different shots of the person.  You take your first shot, and then change your composition and need to move your focus point to be on the person’s eye.  If your camera has 40+ focus points like many DSLRs do, you have to use the four-way selector to tediously move the focus point to the correct spot, focus, and then take the photo.  How annoying!

You can use back button focusing to solve this problem because the distance between the photographer and the subject stays the same between both shots, but the composition changes.  With back button focusing, *the photographer activates focus for the first shot, and then is able to recompose infinite times as long as the distance between the camera and the subject remains exactly the same*.

You’ll note that there are other ways to solve this problem, such as *focus and recompose* (equally tedious, but sometimes it’s your best bet), or holding the AF-L, AE-L button, but that is just plain annoying.  Back button focusing is superior in this instance as long as the photographer is *careful not to change the distance between the camera and the subject (which would throw off the focus) when using shallow depth-of-field*."

******
A great example of THEORY clashing horrifically with the actual practice of portrait or model or lifestyle photography.

1)  Here's a steel-tape FACT. Focal plane at 90.25 inches to X of gaffer tape on wall. Twenty-five degrees to left of the lens-to-target axis, the measured wall-to-focal plane is 97.00 inches distant. That is a 6.75 inch distance disparity. More than the depth of field will cover at wide aperture. Focus and recompose with a 35mm lens will throw the focus off by almost seven inches. The author of this piece suggests that instead of taking .25 seconds to use the jog wheel on the back of your camera, to just skip placing the AF point properly, and instead using using focus and recompose! Wow...how newbish.

And the wording: "*recompose infinite times as long as the distance between the camera and the subject remains exactly the same". *I wish the world were that simple and perfect.


2) Steel tape fact #2: I set up a tripod with the camera plate a measured 47 inches from the floor. With the camera framed in "tall" mode, the center of the frame was a measured  91.25 inches to the wall.  The distance to the ground wall/floor joint, at the ground? 103.25 inches. That means an 11.75 inch focus discrepancy. Very dicey. At wider apertures, this one is a loser.

The guy who wrote the piece above is not a very experienced photographer. But he did figure out how BBF works. And he wrote a nice excited piece about it, but his portraiture technique and knowledge utterly sucks.

He's basically saying, WTF, lock the focus somewhere between 7 inches and a foot off, and fire away. Uhhhh...no. Never. Ever. Photo technique articles that use faulty examples spread misinformation. And that is exactly why so many noobs shoot portrait sessions with EVERY FRAME out of focus, even at 15 feet, with their 35mm and 50mm lenses, even when they had stopped down to f/2.8. Bad advice from people who try to teach stuff they really have no business "teaching". Focus and recompose is a HORRIBLE method if one is so,so lazy as to use the center AF point, then to let go of the button and just blaze away? Just so,so,so wrong on multiple levels.


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## JacaRanda (Mar 17, 2016)

It's very much a YMMV scenario.  As in all things camera and photography related, use what works for you and your camera.
My camera is pretty much always set to AI-Servo for continual focus update.  For a flying bird or any other fast or slow moving subject, I hold my bbf thumb down while tracking and pressing the shutter.  Even when a bird is wading (not moving distance at all), I simply BBF and release it (focus once and done) and again release the shutter as often as I want.  At that point my thumb is free to change anything else it would normally be used for.  Since I have gotten used to using BBF, I don't think I have ever forgotten to refocus.  It simply becomes habit or second nature - just like using the shutter button.  

All it is, is a way to use your camera differently.


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## JacaRanda (Mar 17, 2016)

Overread said:


> I just leave backbutton focusing on and hold the button down for continual refocusing.
> Gives me the same grip on the camera; although I do back that up with a battery grip and wrist strap.
> 
> That's when shooting anything; - landscapes, macro*, wildlife, showjumping, people etc....
> ...



Dang, you beat me to it.


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## SCraig (Mar 17, 2016)

NancyMoranG said:


> Peg, I am using it based on suggestions on TPF. I didn't even know the stuff overead posted (zheezs :{ )
> But I think a lot of people in the Nature forum use it. SCraig and Jaca come to mind. You might wander over there...
> Sorry I can't help much.


Don't know about JacaRanda, but I never use it.  I've never seen any reason to push two buttons when pushing one will do the same thing.  To each their own though.


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## Derrel (Mar 17, 2016)

I'm still laughing about the portraiture scenario where, "*the photographer activates focus for the first shot, and then is able to recompose infinite times as long as the distance between the camera and the subject remains exactly the same*."

Gotta love that kind of a scenario!  That surely exists in the world where all the women are 7's and I am a sold, gold-plated 10.


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## robbins.photo (Mar 17, 2016)

SCraig said:


> Don't know about JacaRanda, but I never use it.  I've never seen any reason to push two buttons when pushing one will do the same thing.  To each their own though.



I tried BBF - wasn't really my cup of tea.  Maybe if I'd had Jaca there to hold the button for me.. hmmmm...


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## NancyMoranG (Mar 17, 2016)

SCraig said:


> NancyMoranG said:
> 
> 
> > Peg, I am using it based on suggestions on TPF. I didn't even know the stuff overead posted (zheezs :{ )
> ...



Whoops, must have been some other tall, daring, handsome TPF member


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## JacaRanda (Mar 17, 2016)

robbins.photo said:


> SCraig said:
> 
> 
> > Don't know about JacaRanda, but I never use it.  I've never seen any reason to push two buttons when pushing one will do the same thing.  To each their own though.
> ...


  That's about all I'm holding for you buddy pal .

Squarepeg - This is exactly why you should try things out.  Know as many features as your modern day camera has in order to use them to work best/easiest for you.  The type of photography you do, may determine how you decide to use your camera.  Good thing the camera makers give us choices - sometimes based on photographers requests.  Not everything on the internet is trying to trip you up.


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## SquarePeg (Mar 17, 2016)

After reading all of this I'm not sure if BBF is right for me but I'll probably give it a try to see how it goes.  I shoot mostly landscapes and flowers and vacation snapshots using AF-S single focus point which I toggle to where I want it.  I've tried focus/recompose and didn't like it.  I don't currently shoot a lot of moving objects or birds in flight but...  I will be shooting my daughter playing softball this spring and cheerleading in the fall so I've been trying to get some practice using AF-C multi point focus on birds, moving cars, our dog etc.  Not a lot of keepers yet but I'm determined to get there.  

Is it possible to set up U1 or U2 as BBF and the leave the other modes on shutter focus?  This may be a dumb question - I haven't read the instructions on setting it up yet...


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## robbins.photo (Mar 17, 2016)

JacaRanda said:


> That's about all I'm holding for you buddy pal .



Such a Killjoy.


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## JacaRanda (Mar 17, 2016)

SquarePeg said:


> After reading all of this I'm not sure if BBF is right for me but I'll probably give it a try to see how it goes.  I shoot mostly landscapes and flowers and vacation snapshots using AF-S single focus point which I toggle to where I want it.  I've tried focus/recompose and didn't like it.  I don't currently shoot a lot of moving objects or birds in flight but...  I will be shooting my daughter playing softball this spring and cheerleading in the fall so I've been trying to get some practice using AF-C multi point focus on birds, moving cars, our dog etc.  Not a lot of keepers yet but I'm determined to get there.
> 
> Is it possible to set up U1 or U2 as BBF and the leave the other modes on shutter focus?  This may be a dumb question - I haven't read the instructions on setting it up yet...



Hoping U1 and U2 are the same as C1 and C2; I have C1, C2 set for BBF and C3 set for shutter button focus.

You won't know if it's for you until you give it a go - and long enough to get used to it.


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## DarkShadow (Mar 17, 2016)

One thing about using BBF is that the dedicated or assigned button feels unnatural and takes some getting used to but also the button is not always in an ideal location as in sometimes its a stretch for the thumb to reach depending make and model. When I had my Canon 6D the AF ON sat higher then where my thumb would rest naturally and would have to reach up for it and that always felt awkward. I never got used to that because it meant my grip hand moving to.  To me the Nikon BBF feels in a better location but still a little to far over from the thumb rest.From what I herd the Nikon D500 brings the BBF closer to the thumb rest for even better ergonomics.


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## SCraig (Mar 17, 2016)

NancyMoranG said:


> Whoops, must have been some other tall, daring, handsome TPF member


You forgot old, tired, grouchy, and stressed


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## robbins.photo (Mar 17, 2016)

SCraig said:


> You forgot old, tired, grouchy, and stressed



Dude.. seriously?  That's my niche.  Lol


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## JacaRanda (Mar 17, 2016)

DarkShadow said:


> One thing about using BBF is that the dedicated or assigned button feels unnatural and takes some getting used to but also the button is not always in an ideal location as in sometimes its a stretch for the thumb to reach depending make and model. When I had my Canon 6D the AF ON sat higher then where my thumb would rest naturally and would have to reach up for it and that always felt awkward. I never got used to that because it meant my grip hand moving to.  To me the Nikon BBF feels in a better location but still a little to far over from the thumb rest.From what I herd the Nikon D500 brings the BBF closer to the thumb rest for even better ergonomics.



Another reason I think ergonomics should be high on the list when purchasing a camera.  Being able to program almost every button on the camera is a plus.
 Most of the weight of my rig is held by my left hand so the grip thing is not an issue.


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## SCraig (Mar 17, 2016)

robbins.photo said:


> SCraig said:
> 
> 
> > You forgot old, tired, grouchy, and stressed
> ...


It's not an exclusive niche, there are quite a few of us.  I'm thinking of starting a club, with me as president so I can blackball whoever I want to.  Be nice and I might let you in though.


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## 480sparky (Mar 17, 2016)

SCraig said:


> robbins.photo said:
> 
> 
> > SCraig said:
> ...



I get to be treasurer!


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## robbins.photo (Mar 17, 2016)

SCraig said:


> robbins.photo said:
> 
> 
> > SCraig said:
> ...


So, will we have a secret handshake?  Lol

Sent from my N9518 using Tapatalk


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## 480sparky (Mar 17, 2016)

robbins.photo said:


> So, will we have a secret handshake?  Lol
> 
> Sent from my N9518 using Tapatalk


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## dennybeall (Mar 17, 2016)

Tried BBF twice - hated it both times. Just too old and set in my ways I guess.......


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## Derrel (Mar 17, 2016)

480sparky said:
			
		

> I get to be treasurer!



You can also be chief electrician, sergeant at arms, official stenographer, and chief cook and bottle washer. SCraig will be head honcho, El Jefe, El Capitan, Le Gran Cheese, as well as president, membership committee director, senate president, and break room key keeper, as well as anti-BBF Promotion Propaganda Minister in Chief. Me and dennybeall will gladly be anti-BBF Propaganda Ministry Ambassadors to Japan...just so we can get diplomatic deals on used camera gear and save 3% on all purchases made on the club's credit card.


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## Dave442 (Mar 17, 2016)

Going from manual focus SLR to a P&S I never really liked the focus being tied to the shutter release. When I started using a DSLR I found the BBF to work just how I wanted so I have stayed with it. I have tried it on the D7000 and don't really like using the AE-L button.

Derrel gives some good arguments for the focus points and dedicating the thumb to selecting focus points. I often focus and recompose, but I also use a focus point close to what I am focusing on. Just checking the example Derrel gave with 90.5" to subject, if I have a focus point to the right third of the frame (9 degrees from straight on with the 35mm lens) it is focused to 91.3" and if I then went to 13 degrees (half way to the edge of the frame) the focus distance is 92.7". So about the extreme that I would recompose off that 9 degrees from center would be halfway back to the center in one direction and over to 13 degrees in the other direction, further than that and I would probably select another focus point further out (and most cameras are limited to just how far out you can select a focus point at). If we go with the full difference from the 90.5" at 0 degrees and at 9 degrees of 91.3" we have a difference of 0.8" with subject being closer than focus point and from the 9 degrees to 13 degrees we have a subject 1.4" further away than the focus point. With a 35mm lens at f/1.4 focused to 90.5" we have 6.6" in front and 7.7" behind the subject appearing in focus per DOF chart (and I like to be more conservative that those numbers). For most subjects that works for me, especially if we do the lean. 

With people I will often focus right on the eye and then fix the crop in post (I only have 11 focus points so can't always put the eye where I want it for the final composition). 

I am excited about the new D500 and the focus point selector toggle next to the AF-ON button (as was introduced on the D4 in believe).


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## Trever1t (Mar 17, 2016)

Derrel said:


> I seldom use back button focusing, but I do use the AF-Lock quite a bit. I know imagemaker46 does not use back-button focus, so it's not that one needs to use BBF, even to shoot action spots, or to be an accomplished shooter.
> 
> I personally think that linking the focusing operation to the trigger in AF-C, and having my right thumb free to move the AF point to the desired area trumps BBF.



This (and agreement with all else) is similar to how I work. I actually set my shutter release to lock AF and AE when depressed to half way in AF-S. In AF-C my shutter button only locks AE when not in Manual mode.


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## imagemaker46 (Mar 18, 2016)

Never used it, never found I needed or wanted to.


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## jsecordphoto (Mar 18, 2016)

I switched a few years ago and haven't looked back. When I briefly had the 7200 I tried using the half pressing the shutter for AF and found it annoying. I would have focus locked on a bird and if I moved a tiny bit, sometimes when going back to shooting I'd press the shutter and focus would shift a bit. It's not for everyone, but I love having the AF and shutter on two different buttons, and the back button on the 750 is in a perfect spot, for me. When somebody hands me a camera now and it's not set to BBF it just seems weird to me now, though it took a few days to get used to at first


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## Watchful (Mar 18, 2016)

I use BBF for most things, but especially for action and sports as it's so much faster than switching manually from center focus to continual focus when the action starts moving.


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## pez (Mar 19, 2016)

I use it most of the time, and the assigned button on my K-3 is in a perfect spot ergonomically. I keep a User function slot programmed with shutter button focusing for a quick switch to conventional mode when I want, or if I hand my camera to someone else, for instance.


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