Back button focusing?

[CapnBloodbeard]

I use it for sports. Haven't really noticed any benefit for it myself though.

Heh, went to the zoo not long after changing the setting, completely forgot I had changed it though. Went through half the day manually focussing because I couldn't work out why AF wasn't working.

[I @ M]

I'm from the why-use-two-buttons-when-one-will-do school of thought, so focus with shutter button for me. Nothing against AF-ON, just never really found a need to use it.


Cheers.

Phil, there is a school of thought that says lenses with VR / IS work at their best when the VR / IS has been activated and then "settled" before the shutter is triggered.

Keeping the VR / IS activated using the rear button is easier than trying to squeeze the shutter to take a shot and then release it to the "half press" needed to activate the VR / IS if using the shutter alone.
There are some instances where the rear button will not offer many advantages over the shutter / focus method, it really depends on the "style" of photography being undertaken but over all I reckon it is a better way to go.

[Glenda]

After reading about it in another thread late last week I set my camera up and used it for the first time Sunday. Was concerned I'd forget it but didn't, found it easy and happy with the results. Probably didn't save any battery that day though as I kept zooming and checking on the lcd screen to make sure it was in focus.

[swifty]

Yes, I use it for the same reason everyone else has stated.
I'm considering buying a different camera for its implementation of this alone (my current camera's back button is too small to access easily for AF-ON). Well not alone but its a big factor, to me at least. I am a bit tho.

[Brian500au]

I have been using it for a couple of years now after reading about it on this forum - now it is just normal. The only downside is I cannot pass my camera off to anybody and ask them to take a pic of me (including my wife) - so I am now living the life of never being in the pic (which i don't mind at all).

[Stingray]

hrmm.. guess I've killed alot of kittens... didn't realise this existed (LOL),
as they say .. we are all learning something new everyday
off to change settings on the 60D and see how it works...
thanks

[oxygen45]

After getting very frustrated today trying to get off shots of birds and constant hunting and switching to MF I made the leap. Brilliant, why did I never use this before? Had read about it a few times and couldn't see the fuss, but after using it I doubt I will go back. Very easy to get the hang of though I suspect it will take a couple more outings to be adequately proficient.

[Milbs1]

I use it all the time have done for a few years now, first thing I change when I get a new camera!

[michaellxv]

I wasn't aware of it. Just looked up how to set it up so i'll give it a try.

[Arg]

There is a nice little (Canon) article, here: http://www.learn.usa.canon.com/resou..._article.shtml

I use it on occasion -- when it is beneficial.

[ROA44]

Found this site which shows how to find/activate for Nikon & Cannon might help someone. I had to still hunt a little as menu was slightly different so just take note of this relevant to your model. I have found & did have a bit of a go Yesterday but need to try a bit more to get a proper feel and look at results but looking positive for me anyway.

http://improvephotography.com/4552/b...tton-focusing/

Hope this helps.

[arthurking83]

Found this site which shows how to find/activate for Nikon & Cannon might help someone. I had to still hunt a little as menu was slightly different so just take note of this relevant to your model. .....

LOL! all you had to do was ask here.

Nikon's at least all have the same basic menu structure, and have had for many years now.
Not all cameras have this feature anyhow. I'm not entirely sure but I don't think the D3000 series, nor the D40/50/60 series before them have this as a feature at all.

AF-On on the models that don't have a dedicated AF-On button have the option in the menu to switch the AE-L button to operate as an AF-On button. These models don't have some of the settings that are associated with the intricate workings of a dedicated AF-On button either.

AF-On usually works best with continuous mode for AF set(but not strictly so) as part of the advantage of an AF-On method for focusing is to decouple the focusing system from the exposure release.

I've seen many landscape images where 'the wrong subject' seems to have been chosen as the point of focus, and this is most likely due to the way most cameras(or at least DSLRs) are setup by default, whereby in AF-S mode the camera's AF system must confirm focus before allowing the release of the exposure.

As an example, in a landscape image it's not uncommon to try to focus on something closer by and shooting with a small aperture trying to get a deep DOF for that scene.
But many folks seem to be stuck in using matrix metering mode, with the centre focus point set in the camera's AF system.
When the camera is set in this way, and the focus has not been set(or moved after being set) the camera may not allow the exposure .. so manual focus may need to be set with the small flip switch on the side of the camera.
Not all folks realize this, and just try to take the shot with the possibility that they think they've focused near to get a deep DOF, yet the camera may then refocus the image(unbeknownst to them) to where the focus point is set(usually the central point) and this is usually somewhere much deeper into the scene, if not at infinity itself.
Then they complain that their lens isn't sharp, or something silly like that.

As others have already said, AF-On is most beneficial in fast paced shooting conditions, once you've taught yourself how and why(which also presumes when and where too! )
But it's also handy for something as simple as a landscape, or any totally static environment as well .. and not for any benefit of focusing, but for the limitation of focusing errors, and/or a better workflow rate .... which eliminates the need to set and unset the camera(or lens) to the M mode for focusing via that annoying little switch (which is usually impossible to reach anyhow).

My AF preferences in camera are AF-On only: AF release unlocked: AF-C mode.

With the advanced cameras with a dedicated AF-On button, you can maintain AF-S focus mode and with the decoupled release still shoot without needing to confirm focus for every shot.
with the cameras that have the optional AE-L switch system, you need to set the camera to AF-C to have the option of not focusing for every shot. That is, you can create beautifully blurred images, without the need to switch to manual focus mode

[MattNQ]

Yup, my d3000 can do it. So I assume the newer base models can do it. I feel a bit dumb now - been dslr-ing for almost 3yrs and had never heard of it.
Doesn't help me for sport, but for other stuff it will be very handy.


sent from a not-very-smart phone via tapatalk

[arthurking83]

I suppose I felt a little dumb not knowing of it back when I had the D70s too I guess.

When I first tried it, using the AE-L button change, I didn't really like it as much, as I tended to use AF-S more with my AF lenses.

If you set the AE-L button for focusing, then try the different focusing modes to complement it as well. Back in the day, we had two focus modes AF-C and AF-S(or nothing .. ie. Manaual). I think most new Nikon's have an AF-A mode, and even tho I now have a more modern Nikon body with this 'mode' .. I have no idea what it is and what it does.

If you set your AE-L button to focusing duties, and maintain AF-S mode for focusing, the camera won't(or shouldn't) allow you to take an exposure unless focus has been made(that's how AF-S mode works.
it's basically setting the camera to prioritise focusing rather than exposure.

But as my primary interest was in landscape photography, once it was explained to me that setting the camera to AF-C mode allowed me to focus where I liked and still shoot without needing to flip the AF/M switch(CSM on higher end bodies) to Manual, and then back for AF duties and so on .. well it just made for a much easier workflow.
So the camera stayed in AF-C mode ... and it's been my preferred focus mode ever since.

Later with the D300, it made even more sense, as the D300 with it's liveview allowed focusing to extreme points in the scene(if desired), but areas that may not have made any sense for spot metering on.
So focus would be set (as an example) way in the farthest reaches of a corner somewhere, but spot metering may have been taken at an opposing corner.

The point is that with AE-L set to focus duties and focus mode set to AF-C, you have a handy hybrid auto/manual focus system .. locked to neither one nor the other type, as long as the lens is not AF-D driven.
And with AF-S lenses mounted, you won't get annoying refocusing issues if your metering point is different to the focusing point.

One slight annoyance with some AE-L buttons, is the placement of them with respect to where a thumb may naturally fall when holding the camera comfortably.
I've just pulled the D70s out of the storage box, and noticed that for my hand size(glove size XL), the AE-L button is a fair stretch for a comfy grip on the camera, whereas the cameras with dedicated AF-On buttons are perfectly setup in terms of distance(to button) and grip size. D70s has always been a bane for me in terms of the size of the grip area .. being too small for my palm.
D300 and D800 are nigh on spot on, whereas D7000/7100 and D600(and smaller) sized camera bodies are too small for me to handhold comfortably for a long stint.

So it's a primary concern to feel comfortable when using a rear button for focusing as the action should be fluent, comfortable and natural to get the most out of it in many varied situations.

FWIW: I've worn out the lettering on the AF-On button on the 'ol D300. It now says A(with half an F next to it) on the button face!
All other controls are in close to pristine condition by comparison.

[Arg]

Oh yes it is!

[geoffsta]

I think most new Nikon's have an AF-A mode

I haven't seen that before. Where is it?

[I @ M]

I haven't seen that before. Where is it?

Push your AF selection button and rotate the front command dial until "auto" shows.

[Mark L]

I haven't seen that before. Where is it?

The link has been posted previously, but if you scroll down it gets to those other cameras that might help you Geoff .... http://improvephotography.com/4552/b...tton-focusing/

I had to search to change my camera. Can't believe it's not highlighted more by the camera makers, as it seems quite useful to me.

[rossco]

never new it was an option until i saw this thread, tried it while learning to dominate my nd filter last weekend, ill never look back, it did take a touch getting used to though

[arthurking83]

..... it did take a touch getting used to though

This is a major sticking point for many.

Also note it also separates the knowledgeable folks from the knowitallwannabesmartypantsexperts too.

Set your camera up with only the AF-On button to focus, and in a focus mode that doesn't allow an exposure, without focusing(ie. focus priority mode)
Next time that loud mouth know it all at the party claims that your images ought to be good as you have an uber expensive camera doing all the work for 'ya ... shove it over to him and get him to take a picture with it .. see how good you can do .... just to show him that the camera is ONLY as good as the operator.

Of course, the camera will not focus for him, nor will it even fire an exposure, because:
A/ he doesn't know how to make it focus
B/ without the camera focusing, it won't allow an exposure.

Shuts 'em up in no time .. and you get back to enjoying the party

LOL! even funnier is watching them try to zoom and focus an old fully manual prime! .. they always ask 'ya .. "how the hell do you zoom?"

(answer is always the same) .... "put your left foot forward....." (at which point they look at you strangely) .. then very slowly explain to them this next part ... "now ... put your right foot further forward".

Initially they look at you funnily .. then it finally sinks in for them .... (answer)"yes, it's not a zoom lens"