Beginner Back Button Focus Question

F70100

F70100

Messages
53
Edit My Images
No
I"ve probably got the wrong end of the stick somewhere about this - I understand that on Canon DSLR's a custom function can assign the focus function to the * button and that the first half press of the shutter button then activates metering only. What I don't understand is what advantage this gives compared with using the * button for metering (its default assignment) and the first half press of the shutter button activating focussing.

Thanks in advance...
 
Pootle over to the sports talk section and do a search on there. There are several threads that explain BBF and its various merits.
 
I use it all the time now since discovering it. It also helps to seperate the focus point to the metering point.
Check out this video by Tony Northrup
Back-Button Focus: Why EVERYONE should use that A…:
 
Last edited:
If I understand it correctly its supposed to make photographing a moving subject easier.

As you can hold focus with the back button and take the picture with the shutter button, as now the shutter button only takes the picture it make that process quicker as you can now hold focus and just press the shutter button as you need it and you dont need to hold hald pressure to maintain focus, especially if you remove all pressure from the shutter button after each photo, as just using the shutter button for both you have to half press to focus then full press to take the picture.

If you are able to hold the half pressure so that focus is always maintained there are no real advantage to using the back button, but if like most, you can't then back button is a big help.

Thats if i understand it correctly though.

Paul
 
Paul-H said:
If I understand it correctly its supposed to make photographing a moving subject easier.

As you can hold focus with the back button and take the picture with the shutter button, as now the shutter button only takes the picture it make that process quicker as you can now hold focus and just press the shutter button as you need it and you dont need to hold hald pressure to maintain focus, especially if you remove all pressure from the shutter button after each photo, as just using the shutter button for both you have to half press to focus then full press to take the picture.

If you are able to hold the half pressure so that focus is always maintained there are no real advantage to using the back button, but if like most, you can't then back button is a big help.

Thats if i understand it correctly though.

Paul
Click to expand...

Imagine you are photographing a particular player in a football match as he runs across the pitch. Another player funs in front of him, so with focus on the shutter button you have to either stop taking photos until he is fully in view again, or let the camera focus on the player in front (whom you are not interested in), then refocus on your subject. With BBF you would simply stop focusing briefly but continue shooting, and you would get your subject, in focus, emerging from behind the other player.

I am not a sports photographer, so bear with me, but I hope that helps. I use it for wildlife in the same way.
 
It also makes the "focus, recompose" method much easier as you don't have to keep your finger half over the shutter button while recomposing
 
I've used it for ages for the reasons above. It took me a little while to get used to it. When my daughter started her A level photography course we got her a second hand 40D, I enabled bbf on it before she got it so she got used to it from the off.
 
IMHO, there are two things BBF does that can't be (as) easily achieved another way.
It allows instant switch between MF/SPF/CF behaviors. And it allows AF to continue to track a moving subject if you inadvertently release the shutter completely between images.

**some of the focus behavior switches are just about as easy to do another way depending on the lens/camera.
 
Best thing I ever did was enable BBF. Once you get used to it you'll wonder how you ever managed without it.
 
^^^^^^:):agree::clap:
 
it is a button-assigning thing. It has to do with how you personally interact with the camera and how the camera responds.

The default is to AF/AEL with the same button: half-pressing the shutter release. This can be annoying for some, who like to pin down the focus first, and then hit the shutter at differnt times. If you keep the default, the camera will try to AF every single time you touch that button which can be a pain in the rear end, especially if light is not good.

So you separate them if that's what you need. AF button to the back. AEL/shutter button to the front. Happy bunny.

It is personal, I like it a lot.
 
Correct me if I'm wrong, but if you set up bbf then you can't use a remote release? Don't you have to be by the camera at all times?

By remote I mean either cable or wireless. If it can be done I'd like to know how because I can't get it to work for me and still have a remote facility which I need.

Anyone know the answer?
 
I have no problem using a remote release on either the 7D or 7D2 with BBF set, perhaps it depends on the camera and/or the style of remote? It only takes a few seconds to swap the buttons round, so it should be easy enough to set focus to the shutter for using remote if you need to, and change it back again afterwards.
 
Using a 5D3 with Canon wired or Hahnel radio control. Can't seem to get focus other than by going to camera and pressing back button. Does away with advantages of remote. Regularly swapping buttons? Do me a favour!!!
 
Ah, I generally pre-focus when using a remote, so that would explain it. I seriously do find swapping buttons only takes seconds though, so that is what I would do if I needed to focus.
 
mickledore said:
Correct me if I'm wrong, but if you set up bbf then you can't use a remote release?
Click to expand...
This is true for Nikons. They must have focus enabled on the shutter release button for a remote to work (maybe not for the built in IR one though if the camera has that). You *can* have AF on both the shutter and BB and a remote release will work.
 
Life was so simple in the old days ... or was it?
 
sports as an example.. normal method when tracking a player is to half press shutter button.. track and when ready fully press and take the picture.. this has many dissadvantages compared to BBF ... 1) the exposure is taken when you half press.. so if the player runs into a shadow you ahve the wrong exposure.. there many ways to setup BBF but mine is so the exposure is taken when you shoot.. so i can track a player running in and out of shadows and when i decide to shoot I get the correct exposure.. 2) half depressing and tracking a player requires a steady finger and not suddenly unhalf depressing... with BBF you simply press the back button and track.. My keeper rate went up massively because of the steadniness of this system.. 3) the recomposure is easy anyway..it just seems quicker and more natural this way

all in all its great for such things as sports and birds in flight that sort of thing.. anyhting that involves tracking I guess.... when i first tried it i didnt get on wiht it.. tried again a yr later and fantastic.. never looked back.... just give it time to get used to :)

PS its great when people say can i try your camera... and they cant focus :)
 
droj said:
Life was so simple in the old days ... or was it?
Click to expand...
Actually the reason I like BBF is that it removes the focus from the capture, just like when I used to focus with the ring on the lens in the old days
 
KIPAX said:
1) the exposure is taken when you half press.. so if the player runs into a shadow you ahve the wrong exposure..
Click to expand...
I don't know of any camera that locks the exposure with 1/2 press of the shutter (at least not by default).

Canon's (some) have a lot more options on setting up BBF than Nikon's do. My D4/810 have no options, it's just enabled or not; metering stays w/ the shutter. And with some Nikons the BB won't activate VR.
The point being, we need specifics before we can talk specifics...
 
sk66 said:
I don't know of any camera that locks the exposure with 1/2 press of the shutter (at least not by default).
Click to expand...

I always set up rear button focus with the AF-ON button, and disengage focus from the shutter release - doing this all my Nikons will lock exposure with half shutter press, this is a major advantage of separating focus and shutter operation.
 
Martyn... said:
doing this all my Nikons will lock exposure with half shutter press, this is a major advantage of separating focus and shutter operation.
Click to expand...
Are you sure? I'm highly doubtful...
I've owned 7 different Nikon DSLRs (D200-D810) and not one locked/locks exposure with 1/2 press of the shutter. Using matrix metering might mask that the exposure isn't locked.

If separating focus from the taking of the image then you probably don't want the metering also separated in many/most cases.
 
Last edited:
sk66 said:
Are you sure? I'm highly doubtful...
I've owned 7 different Nikon DSLRs (D200-D810) and not one locked/locks exposure with 1/2 press of the shutter. Using matrix metering might mask that the exposure isn't locked.

If separating focus from the taking of the image then you probably don't want the metering also separated in many/most cases.
Click to expand...


I have just checked my D700 and a half press of the shutter locks the exposure, the letters AE-L are displayed in the viewfinder.

It was the same with a D80, D300, D800 and my D4.
 
Martyn... said:
I have just checked my D700 and a half press of the shutter locks the exposure, the letters AE-L are displayed in the viewfinder.

It was the same with a D80, D300, D800 and my D4.
Click to expand...

I found it. You've enabled option C1 "AE-Lock" which is off by default. For me, turning that on would be more of a negative (tracking moving subjects). I can't actually see too many times where it would be a real benefit.
I can see it with some meter(focus)/recompose type situations; but the default camera setup allows you to lock exposure separately already (except the D4 which only has an AF-On button).

Why do you find it to be a major advantage (particularly with a D8xx which has both an AF-On and AE-L buttons)?
Just curious, maybe there's something I'm missing...
 
Last edited:
Steve, if I am using the AF-ON button with my thumb, I find it easier to lock exposure with my index finger. I have always done it that way, it feels comfortable to me in use.
 
Karl12347 said:
Just discovered back button focus and love it. How have I gone so long without this function.
Click to expand...

Ignorance is Bliss ;)
It took me a while to get used to it but it does excersie more control imo.....

Oh.....................Now how do i portray Ignorance in a photo to depict Bliss for the 52 in 2015 :runaway:
 
Martyn... said:
Steve, if I am using the AF-ON button with my thumb, I find it easier to lock exposure with my index finger. I have always done it that way, it feels comfortable to me in use.
Click to expand...
I can see it *if* using AF-On... I just don't think that *I* would want that as the default behavior... so maybe "major advantage" in some situations for some people.

Another thing that is probably worth noting is that using BBF with Nikons allows a neat little trick called "trap focus." (it was "broken" on newer models but Nikon fixed it with FW updates)
 
NikonKev said:
Ignorance is Bliss ;)
It took me a while to get used to it but it does excersie more control imo.....

Oh.....................Now how do i portray Ignorance in a photo to depict Bliss for the 52 in 2015 :runaway:
Click to expand...
A dunce hat and an ice cream smile.
 
I have to agree here, setting Back Button Focus is the best thing, in terms of instant results, I ever did to my camera settings.
 
Never even knew what the "back button focus" was until today, looks like a useful "learn".
 
You must log in or register to reply here.
Back
Top