Back Button Focus.

[zombiesniper]

Tried it and as I see it. It's just one more way to complicate things.
One button does both focus and shoot. More simple = more better.

 

[Vtec44]

I use it. It's particularly helpful when you're trying to track something that's moving while you're moving.

 

[SquarePeg]

Tried it and couldn’t see the advantage. Granted I didn’t give it much time. Just didn’t like it.

 

[JBPhotog]

There are numerous occasions when you will want to focus and recompose for framing, isolating the focus to BBAF lets you set the camera in AF-C yet have it function as if it is in AF-S. Switching between AF-C and AF-S is simple not required when you are using BBAF and frees up your shutter finger to select the sub-command dial or any of the Pv or Fn buttons on the front of the camera.

For example, let's say you set a focus point, recompose the camera and then decide you want to change the aperture. If you did this with shutter button AF you'd have to go through the focus and recompose steps again. Additionally the Pv and Fn buttons can have a large number of custom functions which you may want to select after you have focussed and composed, I do all the time.

 

[zombiesniper]

For example, let's say you set a focus point, recompose the camera and then decide you want to change the aperture. If you did this with shutter button AF you'd have to go through the focus and recompose steps again

I could see this on some cameras, Mine has most controls available with a thumb wheel or joy stick accessible on the back of the camera without removing me eye from the eyepiece.

I think basically just use what works for you. Listen to how others like to shoot but it's up to you to find what works for you.
If there was only one way to do it....we'd only ever need one camera.

 

[weepete]

I do find it useful for ballparking hyperfocal distance, focus re-compsing, pre-focus etc. For me it kinda replaces the AF-L and AE-L functions. Bear in mind that I shoot Canon, and therefore don't have focal point linked metering.

For action shots it can help a bit, particularly with pre-focus. Likewise with ND filters, after I release the AF-ON button my focus is locked, so I don't then need to worry about switching the lens from AF to MF and back again.

It may be something I'll have to look at with my new camera, as I think now I can add EC in manual mode and that might be ultimatley more useful especially as I'm relying on the AF and tracking more for action shots.

I don't think it's a case of BBF makes it easier to get more action shots in focus, more just a case of if you like that seperation of focus and metering and if works for the way you shoot. Ultimatley it's just down to personal preference and it's something that has worked well for me in the past though it does take time to get used to.

 

[Overread]

For me its great to be able to decouple the act of taking a photo with the act of focusing the lens. This means being able to shift between continuous AF and one-shot AF without having to change any settings. You can one-shot AF by just holding down the backbutton, focusing, and then releasing your finger. Meanwhile if you want it to keep going you just hold your finger down and it keeps going. Needless to say my camera basically lives in continuous AF - until its sort of dark and I want a flash focusing aid to help me. At which point I spend 10 mins trying to work out why the focusing aid won't fire only to then finally spend time going through the menu to find how to change the AF mode as focusing aids only work in true one-shot AF modes.


Another benefit is if you're using IS/VR. Anti shake systems take time to speed up and start countering shake. During the time that its spinning up to counter shake, most will induce their own blur on the photo. As a result if you point and shoot very fast it can be detrimental. However if you've decoupled focusing and shooting, you can hold down the shutter half way and the meter kicks in metering the scene and the anti-shake kicks in too. You've not started changing focus but the lens is now ready.

And there's another benefit. You can take a complex scene and take meter readings through the camera lens over various parts of the scene without the focus shifting around. This can be a great help because you can easily view the scene as a whole, meter different parts/areas of it, and return view to where you were. Whilst the focus might have shifted a little as a result of you moving the camera and lens around; its overall general position won't have shifted. Great if you're metering things at big distances from each other so that you're not having everything jumping around distracting you.


I think that its a mode many who shoot action and outside tend to focus on slightly more than those who perhaps shoot inside or who shoot in controlled conditions more often than not. Since when you're under controlled conditions you've often a more relaxed situation and its easier to go flicking AF/MF switches on the lens or changing focusing modes. It's also another mode and it does make a one action event into a two action event. However that's where practice comes in. For me its just intuitive for me to hold down the backbutton to start focusing. I've done it for so long I don't have to "think" about it any more, I just do it. For those new to it that extra step can result in missed shots because there's another step to get things going where once they had only one.



I liken it a bit to shifting between auto and semi or full manual modes. In full auto there's one step - point, meter, shoot all on one button. Add in semi manual and manual modes and there's two to three settings you're now responsible for. For people new to it this can really slow them down and make them miss shots. Once you're used to it its second nature and things speed up. Plus, of course, when you do get shots you get better results.

Backbutton AF is slightly harder to draw the line on because even when all the process goes right you can still get AF missing shots; or slight errors in handling can result in missed shots etc...

 

[Original katomi]

This post got my alleged brain working. I looked at how and what I photograph a a bit of a shoving truth emerged.
Apx only 25% of my photos are taken with the shutter release button. I do a lot of images tethered to the laptop
And use that to control the camera otherwise I am using a remote of some description. Most of the time I am using the m setting on the focus.
Looks like I have made a new sub group for your list lol

 

[JBPhotog]

I do find it useful for ballparking hyperfocal distance, focus re-compsing, pre-focus etc. For me it kinda replaces the AF-L and AE-L functions. Bear in mind that I shoot Canon, and therefore don't have focal point linked metering.

For action shots it can help a bit, particularly with pre-focus. Likewise with ND filters, after I release the AF-ON button my focus is locked, so I don't then need to worry about switching the lens from AF to MF and back again.

It may be something I'll have to look at with my new camera, as I think now I can add EC in manual mode and that might be ultimatley more useful especially as I'm relying on the AF and tracking more for action shots.

I don't think it's a case of BBF makes it easier to get more action shots in focus, more just a case of if you like that seperation of focus and metering and if works for the way you shoot. Ultimatley it's just down to personal preference and it's something that has worked well for me in the past though it does take time to get used to.

I'd suggest BBAF does improve your hit rate for action as well as portraits. By separating the two functions you can control when to employ one or the other both.

With portrait work it is especially useful as the focus point is generally not exactly where you want it, the eye. With BBAF you focus on the eye recompose and then shoot as often as you want without having to keep the shutter button half pressed to lock the focus.

With action, say a bird flying perpendicular to you, you hit BBAF and start shooting. If a tree branch or another bird flies between you and your subject the lens will not refocus if you have released the BBAF but still have the shutter button pressed.

 

[Braineack]

I was wondering how many people still use "back button focusing" or is it redundant given the focussing/sensor technology we have in cameras now?

It's all I use. How could it be redundant? It's simply disconnecting the focus acquisition from the shutter release.

There's very little drawback to it, but tons of pros.

 

[wfooshee]

My own take is that I don't see the point unless you have to separate focusing from shutter release, i.e. aim, focus at a specific point, then recompose and shoot at leisure. BBF ensures that no focus changes occur while you recompose. That's much easier than holding the half-press! I never saw any need to use BBF otherwise. With 3D continuous AF I miss very few shots on moving subjects. By very few, I mean maybe 1 in a couple of thousand at an air show, for example.

 

[Braineack]

The ability to focus and recompose easily is a HUGE benefit. It's much easier and faster to do than programming any AF-L. Even more so when you have to take a second recomposed shot -- you just shoot. Otherwise you must refocus and recompose.

Just off the top of my head:

What about shooting in the studio, focusing once and never having to worry about it again. If you setup some scene, you can easily move focus around when using on-shutter-press AF.

Or shooting moving things, you can keep your AF set to AF-C and always track the subject and take a shot at will. Need AF-S, just press the focus button and release it.

It's much easier to require focus on your subject when lining up a shot, or shoot through obstacles with just releasing your thumb.

If your lens is manual override, you can focus it manually without changing any settings.

Shutter will always fire -- I'd rather have slightly off focus, than no shot at all -- this is huge for event photography.

Able to more precise with the shutter timings.


All my cameras are setup for AF-ON and AF-C 100% of the time. It's extremely rare I miss focus in any situation. I can pick up any of my cameras and shoot; simply worrying about exposure settings and not if I need to track the subject or not.

 

[wfooshee]

BBF in action shooting means holding a button while working the shutter. Goofy, to me. Yeah, it can be done, but why require the second button?

The advantage is in focus-then-compose, and it's great for that. Only that. I have spoken.

 

[Braineack]

it's literally the same thing as half-pressing a button while working the shutter, but less fatigue on your finger and better control over the shutter itself...

 

[Overread]

BBF in action shooting means holding a button while working the shutter. Goofy, to me. Yeah, it can be done, but why require the second button?

For action there's several benefits:

1) If you're using VR or IS or any other anti-shake you can enable the anti-shake (half press the shutter) without engaging auto focus. This might be good for enabling the anti-shake before the subject will appear in the frame. So there's nothing to focus on, but you still want the lens ready and working and countering shake for when the subject does appear. If your focus is already in the right ballpark position you don't want it hunting back and forth or focusing way off into the distance when the subject appears

2) You can pre-focus at a specific spot you know the subject/action will be at, but you're also then able to turn the AF on after that point and track movement right after. Eg an animal jumping a showjump you can pre-focus on the jump itself- get the shot as they go over; then enable AF with the backbutton and track the subject as it moves off the jump and away to somewhere else.
Backbutton is far faster at this than trying to find the right switch on the lens barrel for AF/MF switching. Especially as on some lenses the switch can be a long way from where you naturally hold the lens.

3) You can half press to engage metering and meter the scene. The light might be shifting and changing so being able to doublecheck before the action starts, but without losing your focusing point lets you make quick checks even near to action moments.