Back Button Focus, enabling and disabling it easily?

dieselnutjob

Senior Member
I just upgraded from a D3100 to a D750 (about four weeks ago).
The D3100 rarely came out of Auto mode, but now my daughter is doing wonderful things with it so I got to upgrade.
One of the things I saw in Tony Northrup's wonderful tutorial (https://www.youtube.com/watch?v=GmT4wVNTTjE) was Back Button Focus.
Having tried it I kind of get it, especially for focus and recompose, but I'm not sure that I'm 100% all in on this.
After enabling it I then (later on) found myself forgetting to focus.
So then I thought, is there an easy way to enable Back Button Focus (BBF) only when I want it?
The only answer I found is to program it into one of the U1/U2 settings. So for example I can put the camera in P mode, set BBF off and save to U1, then set it on and save to U2.
Now U1 is P without BBF and U2 is P with BBF. All of the others (Auto, P, S, A, M) also now BBF on because that was the last one before saving it. If I had set BBF on and saved it then BBF off and saved it then I think that would make BBF off the default, is that right?
Anyway this seems a little clunky because now suppose I want to reassign the record button to ISO, I have to now save that to U1 and U2 as well which "overwrites" the BBF setting in one of them, so I kind of have to do the BBF on in U1 and off in U2 again.

Is there a cleverer way to do this?

I guess I want an easy way to temporarily use BBF just when I want it? and maybe I want that way to work in all of the modes (Auto, P, S, A and M), and really I suppose I would want continuous focus on as well, and maybe go back to single focus when BBF is deselected.
 

hark

Administrator
Staff member
Super Mod
Contributor
I have my bodies set up for U2 to be BBF, Manual Mode with Auto ISO enabled, plus AF-C. Capped the ISO around 6400 if I remember correctly. Otherwise I use Aperture Priority or Manual Mode normally with AF-S and the shutter button to focus. It's quick to switch between the two types of shooting.

I couldn't get into using BBF all the time though. Using it for stationary subjects (press back button to focus, remove thumb, recompose, fire shutter button) wasn't for me.
 

nickt

Senior Member
No clever way that I know of to jump back and forth. It took me a year to get used to bbf. I quit and went back a few times but I'm all in now. Its become second nature and my thumb finds the button as I pick up the camera.
I'm not a big fan of the U modes, they get confusing. If you make changes without re-saving a a U, they are temporary. They stay for a power cycle but leaving U mode reverts it to the saved settings when you come back to U. Not good for any everyday shooting for me. My U's are set very basic. One is set for shutter button focus and auto everything in case I hand the camera to someone else to use. The other is my 'bigfoot' mode. It is set for my usual bbf settings and auto iso. Its for just in case I am in the middle of doing something special and bigfoot runs out of the woods and I need to quickly get to the bbf settings I'm comfortable with.
Since you are not comfortable with bbf, I would set bbf for one of your U's and just play with it when you have time and maybe it will grow on you. I think for it to be truly handy, it needs to be second nature and your 'everyday' mode. At least that's how it is for me. Last year I tried to set a U to what I felt were good bird in flight settings with shutter button focus. It didnt work out, I'm too used to pushing that back button for focus. Just the opposite of what you are doing now. Back when I first tried it I had the same problem, I'd forget to focus. Then one day it just clicked and I started using it full time.
 

dieselnutjob

Senior Member
I like what you suggest.
U1 = idiot mode
U2 = bigfoot mode
Stay out of U1 and U2 for most scenarios and mess with the settings as you go.
I have only tried BBF for 1/2 hr or so. Maybe I should persevere.

I didn't really need such a complicated camera to be honest, but at £900 for a brand new one it seemed silly to not spend a bit more and buy a camera that can do everything (full frame, screw focus lenses, two SD cards, fold out live view screen, good low light performance). My reasoning was that if I had spent a couple of hundred less on say a D5600 then the first time I can't do one of those things it would have driven me mad.
 

nickt

Senior Member
I like what you suggest.
U1 = idiot mode
U2 = bigfoot mode
Stay out of U1 and U2 for most scenarios and mess with the settings as you go.
I have only tried BBF for 1/2 hr or so. Maybe I should persevere.
The beauty of bbf is that it gives you af-c focus when you hold the button (good for tracking) and a simulated af-s mode (good for focus-recompose) when you release the button. It ends up being very handy to jump between focus modes like that. I have described it to people as power assisted manual focus. Used with single point focus, you have the ability to put that single point on your subject and either track it or release the button for a one-time focus. If I'm shooting birds in flight I'll either leave it single point or sometimes go with d-9 for smaller birds. Its very important when using this technique that you are in af-c focus mode with menu a1 set to release priority. Some people new to the technique don't get that and leave it in af-s and things don't work the way they read about it. The magic is not that you are using the back button but its that you have the instant ability to auto focus or not to auto focus. Its a lot like manual focus, but with some help. Have fun.
 
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