# Back-button focus?



## tayassu (Aug 29, 2014)

I watched a video about back-button focus recently. Seems great... Are there any negatives whilst using it, e.g. not locking focus properly on near still subjects? Are you using BBF? Thanks for any input!


----------



## neuroanatomist (Aug 29, 2014)

I use BBF, in One Shot for still subjects and in Servo for moving subjects (different C# settings). 

The only significant drawback is if you hand the camera to someone so you can be in a picture, they'll most likely expect a shutter half-press to focus. Not an option for me, but 'green square' mode puts focus back on the shutter button.


----------



## mackguyver (Aug 29, 2014)

I use it 100% of the time and have for many years. The only negative is if you forget to disable it before handing your camera to someone else to take your picture. A blurry shot is all but guaranteed. Other than that, the additional control from the separation of functions is well worth getting used to it. Just make sure you have a custom setting for other people that has it disabled...assuming you let other people touch your camera


----------



## privatebydesign (Aug 29, 2014)

I found my thumb got tired and, because I am slow to learn, I missed lots of shots because I forgot to push the focus button, so I changed it to BBF OFF, this switches the focus off when you push the back button, I have found this far more reliable, it induces less thumb fatigue and I am much better when looking through the viewfinder of thinking "I don't want that to mess up AF" and pushing the AF OFF button, than remembering to push the AF button all the time apart from the few times I want it off.

Try both, but don't think because you read it, or some pro recommends it, it will make most sense for you, that is the greatest thing about the customisation options we now have, we can make our cameras best for us.


----------



## mackguyver (Aug 29, 2014)

privatebydesign said:


> Try both, but don't think because you read it, or some pro recommends it, it will make most sense for you, that is the greatest thing about the customisation options we now have, we can make our cameras best for us.


Well said and personally I'm still trying to figure out what to do with all of the customizable 1D X buttons almost six months after buying the camera!


----------



## DominoDude (Aug 29, 2014)

I'm using it since day one on my 7D, and I can't even imagine going back to shooting without it. If there would be any drawbacks it would be that since your thumb is occupied pressing the AF-On button, you won't be able to fiddle with the joystick or controlling the dial on the back at the same time.


----------



## tayassu (Aug 29, 2014)

Thanks for your input!  I will try out!


----------



## Besisika (Aug 29, 2014)

neuroanatomist said:


> I use BBF, in One Shot for still subjects and in Servo for moving subjects (different C# settings).
> 
> The only significant drawback is if you hand the camera to someone so you can be in a picture, they'll most likely expect a shutter half-press to focus. Not an option for me, but 'green square' mode puts focus back on the shutter button.


+1


----------



## amfoto1 (Aug 29, 2014)

tayassu said:


> I watched a video about back-button focus recently. Seems great... Are there any negatives whilst using it, e.g. not locking focus properly on near still subjects? Are you using BBF? Thanks for any input!



BBF is particularly useful if you shoot a lot of moving subjects and often have your camera in AI Servo focus mode. BBF is the only way to be able to do "focus & recompose" technique in AI Servo, for example. It also makes easy "dodging" any sort of object that's momentarily between you and a subject that you're tracking. 

BBF isn't the answer for everyone, and it does take a little time to get used to it. But once learned, it's hard to think of going back to the default method. 

It can be used with either AI Servo or One Shot. But once you have learned BBF you likely will find yourself using One Shot a lot less. You can stop or "lock focus" on a subject while still in AI Servo, simply by lifting your thumb off the button... very similar to what's done by One Shot. 

One advantage to BBF is when using any varifocal zoom... Many modern zooms are this design (it's cheaper and easier to build). They don't maintain focus when you change the focal length. Continuously holding down the button with your thumb, with the camera in AI Servo, will continuously correct focus while changing the focal length of a varifocal lens. (Same thing can be done using the standard button assignments, but if using One Shot you have to remember to lift pressure and reapply it, to cause the camera to refocus, after making any change to the focal length of a varifocal zoom.) 

I see you have 7D... 

On 7D (and most other current models I'm aware of)... to set up BBF you don't have to enable anything. It's already assigned to the AF-On button on the back of the camera. Instead you go in and_ disable _AF from the shutter release button. 

Optionally you can swap the function of that button with the * (AE Lock) button. I do this, because the * button is larger and more prominent, not to mention closer to my thumb. I focus every single shot, so it makes more sense to me, to have the * button serve that purpose, and to reassign the less frequently used AE Lock function to the AF-On button.


----------



## eos650 (Aug 29, 2014)

I prefer the opposite. I used BBF on all of my bodies for over a year and I shoot daily.

Although I like the ability to disconnect focus from the shutter button, traditional BBF was not for me. I didn't like the fact that I was constantly having to do two things (hold the BBF button and squeeze the shutter button). In my case I found squeezing both sides of the camera, made it harder for me to hold steady. It also caused more fatigue while shooting sports in AI Servo for hours on end and tied up my thumb.

Instead, I leave focus attached to the shutter button, but program the BBF button to disable focus, when pressed. This works much better for me. It allows me to concentrate on the shutter button most of the time. In the situations where an object passes between me and my subject or in cases where I simple want to lock focus, I then push the BBF button. I don't have to hold the button constantly while shooting. I only hold it, when I want to to disable focus, which is a far smaller amount of time.


----------



## Steve Balcombe (Aug 29, 2014)

For most situations I don't like back button AF. It's a big ergonomic disadvantage to have to use your thumb as well as the index finger to take a straightforward shot. Plus the thumb is needed to operate the joystick, or the wheel to adjust EC.

However I have found one exception, and that's macro shooting. Most of the time I want manual focus, but just occasionally AF is useful so instead of switching the lens to manual I set the body to back button AF. I have a convenient set of macro defaults including this assigned to C1 on the 7D, or C on the 60D, so I can switch to it (or just as importantly, from it) at any time.


----------



## JonAustin (Aug 29, 2014)

I used to use BBF exclusively, but haven't for the past couple of years. I can't even say why I changed back to shutter button half-press for focus, but that's where I've been ever since. 

If I need to decouple focus from the shutter button for any reason, I'm much more likely these days to switch to manual focus.


----------



## Marsu42 (Aug 30, 2014)

JonAustin said:


> If I need to decouple focus from the shutter button for any reason, I'm much more likely these days to switch to manual focus.



Inspired by a post in this forum, I recently changed my cameras to use "af off" on the "AF-ON" button. It needs holding down while focusing, but is quicker than to reach for the af/mf lens switch. Pity there is no "af off (hold)" option.


----------



## tayassu (Aug 30, 2014)

Thanks for all your help! 
I tried out the different techniques and I have now configurated the shutter button for AF and the AF-On button for AF-Off, as privatebydesign first suggested. As you say, it's personal taste, I like it better than vice-versa. Thanks again!


----------



## HankMD (Aug 30, 2014)

One possible drawback: cable release no longer activates focus. 

This is to be expected, of course, but I was nevertheless surprised when I decided to practice using a cable on my BBF'ed camera. I briefly switched back to the default but I had been using BBF for a year now and had difficulty going back. I think I will have to learn to focus with the BBF button, THEN trigger release with cable.


----------



## Northstar (Aug 30, 2014)

Tried it for a few weeks...then quit and went back to shutter. I shoot sports, I just couldn't get comfortable with it.


----------



## JonAustin (Aug 30, 2014)

HankMD said:


> One possible drawback: cable release no longer activates focus.
> 
> This is to be expected, of course, but I was nevertheless surprised when I decided to practice using a cable on my BBF'ed camera.



Maybe _that's_ why I stopped using BBF ... (Early onset Alzheimer's is a bitch!)


----------



## FTb-n (Aug 30, 2014)

To me BBF is the most natural way to use the camera. It seems most inuitive that focusing and tripping the shutter are two distinct actions that should be done with two distinct buttons. Since I most often shoot in full manual mode, I like to have focus and exposure set before tripping the shutter and don't want the shutter button changing one of these settings.

The biggest drawback is handing he camera to my wife, who isn't used to it. But, my kids took to it quickly.

The is, however, one case where I may reassign focus to the shutter buton. When shooting a 90 minute figure skating exhibition in AI SERVO, it can get tiring to sit on the BBF button for most of the event, even when using a monopod.


----------



## terminatahx (Aug 31, 2014)

I need to try this on my next football game. Sometimes I do miss shots with the default shutter focus setting. Especially in situations where the action is full of bodies flying around.


----------



## sagittariansrock (Aug 31, 2014)

Marsu42 said:


> JonAustin said:
> 
> 
> > If I need to decouple focus from the shutter button for any reason, I'm much more likely these days to switch to manual focus.
> ...



Not sure I understand...
If you use BBF, your system is essentially on manual focus (AF off- hold) unless and until you press the back button...


----------



## privatebydesign (Aug 31, 2014)

sagittariansrock said:


> Marsu42 said:
> 
> 
> > JonAustin said:
> ...



I think you will find Marsu has AF on the shutter button and the AF-On button set to AF Off, that means if he wants to manual focus he just pushes the AF-On button (that turns AF off).


----------



## sagittariansrock (Aug 31, 2014)

privatebydesign said:


> sagittariansrock said:
> 
> 
> > Marsu42 said:
> ...



Oh, I understand his set up  
What I could not understand is why he can't set AF-On on the back button, and no AF function on the shutter button, essentially making it AF off-hold until and unless he presses the back button (since he was wishing for an AF off- hold scenario).


----------



## privatebydesign (Aug 31, 2014)

sagittariansrock said:


> privatebydesign said:
> 
> 
> > sagittariansrock said:
> ...



Because many people find needing to use their finger and thumb to AF and expose inefficient, especially if you regularly move AF point with the joystick or work EC with the back dial, or if you are in M mode adjust aperture with the back dial. I tend to use my thumb for other stuff and found I got thumb fatigue with BBF, I really like the AF-On button set to AF off, I find it works well for me and the other stuff I want to do with my thumb.


----------



## sagittariansrock (Aug 31, 2014)

privatebydesign said:


> sagittariansrock said:
> 
> 
> > privatebydesign said:
> ...



Ah, got it. Thanks!


----------



## Marsu42 (Aug 31, 2014)

sagittariansrock said:


> Ah, got it. Thanks!



Thanks all for explaining . Indeed I do ec correction with the back dial all the time, and even change af points even with the 6d - so my thumb is allocated elsewhere. That's also the reason why I use expo lock _(hold)_ on the * key. BBF would be overkill since I af 95% of the time for wildlife.


----------



## pwp (Aug 31, 2014)

privatebydesign said:


> I found my thumb got tired...


And I thought I was the only one to get thumb fatigue! 
Back button focus is a brilliant option for photographers with better thumbs than privatebydesign and myself.

-pw


----------



## Phil Lowe (Aug 31, 2014)

Northstar said:


> Tried it for a few weeks...then quit and went back to shutter. I shoot sports, I just couldn't get comfortable with it.



The thing I like most about it is the ability to leave my camera in AI Servo mode, and stopping focus by just releasing the button. I find I never have to switch to one shot focusing mode anymore. 

I own and shoot the 5D3, 7D, and occasionally, the T3i, which is a great little travel camera.


----------



## langdonb (Aug 31, 2014)

amfoto1 said:


> tayassu said:
> 
> 
> > I watched a video about back-button focus recently. Seems great... Are there any negatives whilst using it, e.g. not locking focus properly on near still subjects? Are you using BBF? Thanks for any input!
> ...


I have been using BBF for some time on 6D. Now I have 5D3 and trying to learn some BIF techniques using Ai focus. 

Do you constantly hold the BBF down while tracking a BIF (using 61 pt AF or another setting?)?


----------



## neuroanatomist (Aug 31, 2014)

langdonb said:


> I have been using BBF for some time on 6D. Now I have 5D3 and trying to learn some BIF techniques *using Ai focus*.



I'd stick with AI Servo for BIF. The idea behind AI Focus is that if you start with a still subject it uses One Shot, then tries to detect when the subject starts moving and switches to AI Servo. IMO, it doesn't do that very well. The 1-series bodies have One Shot and AI Servo, but no AI Focus...there's a reason for that.


----------



## jalbfb (Aug 31, 2014)

HankMD said:


> One possible drawback: cable release no longer activates focus.
> 
> This is to be expected, of course, but I was nevertheless surprised when I decided to practice using a cable on my BBF'ed camera. I briefly switched back to the default but I had been using BBF for a year now and had difficulty going back. I think I will have to learn to focus with the BBF button, THEN trigger release with cable.



I've been using BBF for several years now and can't see ever going back to shutter release focus. The times that I am using cable release, my camera is on a tripod and I've locked focus either in live view or through the viewfinder with BBF after composing my capture and then firing off the cable release. All of those pictures are static landscape or portrait type pictures. I am not sure why someone would have or of a problem with using the cable release with either shutter button focus or BBF.


----------



## willis (Aug 31, 2014)

I really like back button focus it gives so much more control on camera. Basically on 7D I changed that it only meters on shutter and focuses only from that AF button.
Single shot for stills (landscapes)
Servo for moving objects for sports is just amazing.

For example if you are taking pictures of baseball you can use servo through whole session. First to use it focus to a batter so it locks on to him when batting, when he starts to go to first base you can just press AF button to start tracking him down the field.


----------



## langdonb (Aug 31, 2014)

neuroanatomist said:


> langdonb said:
> 
> 
> > I have been using BBF for some time on 6D. Now I have 5D3 and trying to learn some BIF techniques *using Ai focus*.
> ...



MY bad....I did mean Al servo mode. My question is in that mode, when I target a BIF or any other moving object, do I capture focus and then continue to hold the BBF button down while capturing images?


----------



## neuroanatomist (Aug 31, 2014)

langdonb said:


> MY bad....I did mean Al servo mode. My question is in that mode, when I target a BIF or any other moving object, do I capture focus and then continue to hold the BBF button down while capturing images?



Yes, keep holding the AF-ON button while tracking and shooting. However, depending of the flight direction of the bird, you may want to look into a technique referred to as 'bump focus'.


----------



## langdonb (Aug 31, 2014)

neuroanatomist said:


> langdonb said:
> 
> 
> > MY bad....I did mean Al servo mode. My question is in that mode, when I target a BIF or any other moving object, do I capture focus and then continue to hold the BBF button down while capturing images?
> ...



Thanks Neuro, I looked that up and have actually used that technique in the past...

What do you prefer as to AF point selection for moving objects? Auto zone, 61 pt AF or??

Thanks for your posts, I read them often on any subject. You have helped me many times!!i


----------



## neuroanatomist (Sep 1, 2014)

langdonb said:


> What do you prefer as to AF point selection for moving objects? Auto zone, 61 pt AF or??



Depends on the subject. For birds, I usually use 1+8 expansion. For people, I do use 61-pt auto.


----------



## michi (Sep 1, 2014)

Ever since I heard about BBF I have been using it. Absolutely love the idea of disconnecting the AF from all other processes. I use it on my 7D, 5DII and even the SL1. I do have to say though that I don't have big hands, and it is certainly not a comfortable grip/motion. Very painful after a long day of shooting. It puzzles me why Canon won't put a customizable button a little further down. It would make it so much ergonomic to use...


----------



## Marsu42 (Sep 1, 2014)

michi said:


> It puzzles me why Canon won't out a customizable button a little further down. It would things a lot easier...



With Magic Lantern, you could switch keys and put the SET function on AF-ON and vice versa. If you use BBF a lot, SET might be easier to reach, at least on some camera bodies. It's not included in the standard ML distribution, but there are other key swtiching/simulation functions already there and you'd only have to copy/paste the code.


----------



## wickidwombat (Sep 1, 2014)

Marsu42 said:


> michi said:
> 
> 
> > It puzzles me why Canon won't out a customizable button a little further down. It would things a lot easier...
> ...



really? didnt know that

can you program the rate button to activate AEB like a 1D does with its button press?


----------



## Marsu42 (Sep 1, 2014)

wickidwombat said:


> can you program the rate button to activate AEB like a 1D does with its button press?



I'd say yes, the RATE button can be intercepted by ML (see /platform/5D3.113/gui.h) and any other possible function can be performed. This includes simulating other keys or directly accessing Canon DryOS functions that have been discovered. Activating Canon AEB (and setting it to different spacings/settings on consecutive keypresses if you want it) should be among them.

If you want this implemented and cannot hack together a module yourself after looking at the sample code, do a detailed feature request in the ML forum and explain why this is important to a broader userbase. It should be pretty easy to do, I changed several buttons on my personal 6d ML build. ML is nearly feature-overloaded as it is so adding yet another one might need some persuasion: your request is rather specific and the ML guys prefer their own bracketing over Canon's version.

http://www.magiclantern.fm/forum/index.php?board=24.0

ML badly needs a button manager for these things, but it's a lot of gui work so no one has had the enthusiasm yet. You also might get the reply that this isn't something to be added in C code, but by user scripting - but afaik this is wip and doesn't work atm (yeah, 3 internet geek abbreviations in one sentence :->).


----------



## sagittariansrock (Sep 1, 2014)

michi said:


> Ever since I heard about BBF I have been using it. Absolutely love the idea of disconnecting the AF from all other processes. I use it on my 7D, 5DII and even the SL1. I do have to say though that I don't have big hands, and it is certainly not a comfortable grip/motion. Very painful after a long day of shooting. It puzzles me why Canon won't out a customizable button a little further down. It would things a lot easier...



Interesting... I thought people with longer fingers had problems with BBF. I have short ones, and the distal joint of my thumb naturally rests on the button in case of the 5Dc (less ideal, but works) and the tip sits naturally on the button on my 5DIII. I would think it would be tiresome to bend the thumb back to a button that is placed lower.


----------



## Hannes (Sep 1, 2014)

I tried BBF for a while but could never really get on with it but I did like the ability to stop AF when in servo mode so it is now set up for AF stop instead and that has worked really well for me.


----------



## the blackfox (Sep 1, 2014)

i always found it was more comfortable on nikons in use .but since returning to canon i find thats its really great for b.i.f ,does get a tad uncomfortable after a while on a 1D body though due to weight and reach ,(saying that i have limited use in my right thumb though) but its definitely the way to get consistent shots imho


----------

