Back Button Focusing

[Cricket]

This term came up in another post I have been reading.

Back Button Focusing??????????????????????? Well I have never heard of it lol. So off to google for some research. I think that putting myself as an intermediate photographer for this forum may have been a mistake. Just because I had taken a few photos does not make me a photographer. Maybe beginner might have been more appropriate.

I still find the whole concept of back button focusing confusing but can see it will be a big advantage when I can understand and master it. In fact the whole thing about understanding how my camera focuses will be an enlightenment to me.

I have now read pages and pages about focusing and back button focusing. Is there an easier way to engage it and understand it? I have a Canon 60D

[J.davis]

UTube is your friend

[Cricket]

Thanks John I have already watched a couple of videos.

[Greg Johnston]

I use it all the time and love it.

[Morgo]

Think of it like this, using BBF you have the option of single shot focus and AI servo at the same time with out changing the cameras AF drive settings
Normally when you take a shot the half press of the shutter button will focus, then the full press takes the shot.

BBF moves the half press of the shutter button to focus to another button but leaves the shutter button to still take the shot but it does not focus. It can be funny to let your friends use your camera as they never get any in focus shots as the shutter button which is all they are using is no longer working the focus

Set the camera AF drive to AI Servo and leave it there. I generally also have high speed continuous on.
For a portrait shot, press and hold the button assigned for BBF, focus on the eyes and release the BBF button. Recompose the shot and press the shutter button to take the shot.
For action, no settings changed, press and hold the BBF button and follow your subject (your in AI servo so your continuously focusing while tracking) press the shutter button whenever you want a shot.

[arthurking83]

T.....

BBF moves the half press of the shutter button to focus to another button but leaves the shutter button to still take the shot but it does not focus. ......

Yep! the main point is that it frees up the shutter button(the release) to do just that .. actuate the shutter.

So, the advantage is that your shutter finger is always on the shutter, and you can have it half pressed(and it does nothing).
Your thumb is always on the AF-On button * and you activate/deactivate focus as you please.


So lets say you're chasing a small bird that's hard to focus on(because it's small and fast). But at some point the bird does come to a rest, even if only for a micro second.
It may be perched in a tree with many distracting branches and those branches can easily confuse AF systems.
AF systems are good, but they're not smart like humans are.
Humans are smart, in that they know what they want in focus, but they're incapable of achieving that process quickly themselves.
AF systems are smart in that they know how to focus quickly and accurately, but they're incapable of understanding what the subject actually is!(or what the human wants).

With the above situation, the human uses the AF-On focus set up to continually AF .. then stop(if the camera focused on the branches .. then on, and off .. until the focus suddenly hits the bird!
All that time, with the human activating the AF-On button .. on and off until focus is hit, the shutter finger(usually the forefinger) is always half pressed and hence ready to hit the exposure faster.

I have the Nikon 105mm f/2.8 VR micro(Macro) lens, and without the AF-On method of focusing .. this lens would be close to unusable in many instances.

So if you've ever had a situation where the AF is getting confused(easy to do on that Nikon 105 lens!), or hunts a lot .. AF-On is you're friend.
Also, landscape photographers can use this method to their advantage, without having to continually change their camera settings for other non landscapey stuff.

Lets say that the landscape person likes to shoot other stuff occasionally too, but that stuff needs a different focusing method. It may require AF-S type focusing.
The problem with single shot AF in many cameras is that it locks the shutter release until focus has been achieved, so you switch to AF-C instead(coz it drives you stark raving mad!).
But if you're shooting landscapes and you have focus set up via the shutter actuator, then every time you take a shot in your landscape quest, it focuses.
Usually this may not be a problem, but when you've set yourself up on a tripod and you know there may be a bit of a wait until the conditions are spot on, there is usually no need to refocus, and usually if it does, it does so along the wrong plane.
So the landscape photographer loves this setup because the smart camera doesn't now have the ability to stuff up their landscape shots!

[Mark L]

I'm sure you'll see what I said in the bird forum, but just in case, Canon don't make it to easy to find how to change your camera to BBF. In the cameras menu go to setting custom functions( page 250 of your manual), then go to the last thing on page 257, Af and metering buttons.

I don't understand why BBF is not the default settings for cameras? It is quite easy to get used to.

[Dug]

I was apprehensive about trying back-focus button setup at first in case I forgot to use it and fell back into old habits, but it became second nature soon enough.

Before using this technique my shooting habits where to focus on a point that made optimal use of the chosen DOF then have to carefully keep the shutter button half pressed while moving to the actual composition, then fully press for shutter release.
Accidentally go either side of the half press and you had to start again. It also made me feel rushed which I did not like.

Its a bit like the days of manual focus for me, I would use the central focusing aid on the focus screen of a film camera, get focus, then forget about the focusing part of it and concentrate on composition and exposure.
To that effect my digital camera only has the centre focus point activated, whatever that point is on becomes my focus point with the press of the back-focus button and it stays there.

Well that's my utilization of the setup. It is interesting to read of other uses for difference scenarios.

[Cricket]

Have had a read and played with Back button focusing. I will need to develope new habits and break old ones I have been around other photographers in the last year or so and I have noticed that experienced photographers forget to mention the every day things they have learned and forget to pass them on to inexperienced photographers forgetting that we all have to start somewhere . I really appreciate the help and information I have so far received on this forum in only a couple of weeks such as back button focusing, exactly how servo focusing works (for Canon), some post processing hints I have picked up and info to start looking on the web.

[Mark L]

Have had a read and played with Back button focusing. I will need to develope new habits and break old ones

Develop the new habit, it won't take long.
It really is worth taking the focusing stress of the finger getting ready to press the shutter button.
I used to take so many photos I didn’t want 'cause the finger on the shutter was getting tired of refocusing and then pressing.

[Tannin]

Be aware of another very valuable technique: reverse back button focusing. After setting your camera up appropriately (very similar to the way you do it for BBF), shoot as normal. Use the shutter button half-press to focus just as you always have. After all, that is the easiest and it works fine for ~90% of all shots. (Some genres are a bit different - I suspect that sport and action photography are both examples.)

When you DON'T want the focus to change, press and hold the back button. For example, to focus and recompose, place your AF point where you want it and half-press the shutter. Press the back button and re-frame as desired. Now take the shot.

BBF or reverse BBF? Neither one is superior, they are just different. Use whichever one works better for you.

[Brian500au]

I find one of the biggest advantages of BBF is cutting the lag time down of the shutter button. Here is a clear example - I quite often like to take a shot of my wife doing a crazy jump when we are travelling somewhere (just a different shot to just standing in front of a landmark monument). In order to get her mid air and at the top of the jump I will BBF whilst she is on the ground and half press the shutter button to be "half way there". Now as soon as she jumps I keep my thumb on the BBF button (AI mode) and simple complete the press on the shutter button. My success rate in using this method is near 100%.

I say this because when I pick up her camera and she has shutter button focus, I can nearly never get the shot first time - and I feel clumsy that I don't have full control over the timing of the focus.

[swifty]

Its hard to go back once you're used to BBF.
In fact, that's my biggest gripe when choosing my smaller travel camera since this ability to assign focus to the back button is not always available on smaller cameras and when it is, the back buttons aren't always well positioned or sized for such a crucial function.
I then have to revert back. Not such a big deal but you know how it is once you get used to something you like.

[glennb]

Yep I recommend back button focusing, I have my D610 set up as back button focus and I use the 1/2 press on the shutter button to hold exposure if/when I need to re-compose the shot.