Back Button Focusing ???

[d70girl]

I keep reading on a few other forums about "back button focusing", and I feel like a dummy for not knowing, but... what is this? I was able to change my settings on my Nikon d70s to do it (I think) but I still don't really know what the difference is, what the advantage is over "regular" autofocus, etc.

Someone said that back button focusing allows you to lock your focus and then re-compose your shot, but... that doesn't really make sense to me.

Can anyone enlighten me?

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[Sw1tchFX]

If we were to use 'back-button' focusing on our D70's, we'd go into the custon menus where the AE/AF lock button is and change it to AF-ON. That way the shutter only trips the shutter and to enable autofocus, than you press the AF/AE lock button. It's a preference thing, i know people who use it becuase they were used to 35mm cameras that did that. I prefer the AF on the shutter.

[d70girl]

So does it give you BETTER focusing? I've heard other people on forums say that they had out of focus pictures all the time before switching to back button focusing. I'm just trying to understand how it would give you better focus.

[Big Mike]

It doesn't give you better focus...but it gives you more control over when the camera is auto focusing. Normally, the AF is tied to the shutter release button...which means that if you have AF turned on...it will be active every time you take a picture. If you want to take a photo of Frank, but the camera's AF focuses on Betty instead...then you have a problem.

By moving the AF to a different button...you can focus the camera on what you want, Frank, and then compose and shoot the picture without activating the auto focus again.

You can, of course, do this without moving the AF to a different button because most cameras will allow you to 'lock' the focus by focusing and holding down the button half way...but many people find it easier to just move the AF activation to a different button.

[d70girl]

Ahhh, ok. Thanks, Mike. It's starting to make more sense now.

[markc]

I use this myself on my Canons using custom function 4. With my eyes, I have trouble with manual focus, so I pretty much have to rely on autofocus. I also have some muscle control issues. It's much easier for me to press a button with my thumb than try to hold one down halfway with my finger without accidentally letting go or tripping the shutter. I rarely have the subject in the center, so this way, I can put the subject at the center focal sensor, press my thumb to focus, let go, recompose, and then trip the shutter. It takes some getting used to and it's not for everyone, but even before my muscle issues, I fell in love with using it. You won't ever get the camera wandering to the background just as you are about to take a shot.

[fmw]

AF lock goes back to the beginnings of autofocus. It still works the same on my digital cameras as it did on the F4. I focus on what I want, push the shutter button down part way, recompose while holding the shutter button and then fire. Really simple.

My cameras have an array of little AF brackets all over the viewfinder that you can select to determine where the AF focuses. I can't believe people would actually use this feature. What a hassle. AF lock is quick and simple. You should learn to use it.

I'm willing to bet that 75% of the gadgets and settings on the digitals is just some kind of feature escalation for competitive purposes. Most of them have little to do with making images or making the camera easier to use. I only ues two metering modes, as an example - P and M. I think the camera has about 8 of them.

I spent a couple of hours figuring out how to make the pop up flash fire the accessory flash unit. After I figured out, I discovered that when the accessory flash unit goes into the power saving sleep mode, the pop up flash won't wake it up. You actually have to turn the thing off and on again to wake it up. What a hassle. I've gone back to the ever reliable extension cord. It fires the flash even when it is asleep.

And what is the purpose of having manual focusing if the viewfinder provides no focusing aids? It simply isn't accurate enough for me. I'm forced to use AF. I would trade all those stupid little focusing brackets for a split image focusing aid in a minute. Ok, Ok. I'll stop now.

Just keep it simple and you're likely to get better images.

[markc]

I'm willing to bet that 75% of the gadgets and settings on the digitals is just some kind of feature escalation for competitive purposes.

I don't know if you were referring to the feature we were talking about, but it goes at least a little back before digital. I first learned about it on my A2e which was introduced in '92. It's basically an alternative to focus lock.

Like you, I have my focal sensor locked on the center one. I've never cared for the eye focus or manually trying to cycle through them.

[Sw1tchFX]

the pop up flash won't wake it up. You actually have to turn the thing off and on again to wake it up. What a hassle. I've gone back to the ever reliable extension cord. It fires the flash even when it is asleep.

What are you talking about? the speedlight or the camera? my SB-600 doesn't go to sleep if i have it in the slave mode.

[fmw]

What are you talking about? the speedlight or the camera? my SB-600 doesn't go to sleep if i have it in the slave mode.

Mine does. It is an SB800.

[ksmattfish]

It doesn't give you better focus...but it gives you more control over when the camera is auto focusing.

And exposure lock is usually tied into the shutter release button. I don't use AF, but if I did I'd need AF lock and exposure lock on two different buttons.

[Sw1tchFX]

Mine does. It is an SB800.

Wow, That's really stupid that it does that. Can you turn the sleep mode off? I'd imagine you could beucase that's just a dumb move on nikon's part if you couldn't.

[fmw]

Wow, That's really stupid that it does that. Can you turn the sleep mode off? I'd imagine you could beucase that's just a dumb move on nikon's part if you couldn't.

I don't know. It could be because the thing always says standby and maybe there is a way to turn that off. I found the the whole thing to be non-intuitive - very hard to figure out. I can get to the secondary menu but can't get out without rebooting the electronics. The manual is awful and the design of the menus is even worse. The flash works just great in TTL mode with an extension cord. That's the way I use it.
I spent over 3 hours with the flash and manual trying to get things to work as explained and just gave up. Good flash, bad user interface.

[Sw1tchFX]

I heard the SB-800 had a bad interface, and that's one of the reasons i went with the SB-600. That and I didn't need the extra $100 worth of 'features'