AF-ON how many use it and what are it's merits

Started Mar 12, 2007 | Discussions
Tom Christiansen Senior Member • Posts: 2,239
AF-ON

winnie wrote:

I just tried this out and I am not sure I get this at all.

I set the AF-ON to be the only focus mechanism in the menu and sure
enough that is all I could use to focus, fine up to this point. If
I then release the button and move away from the focused area I
couldn't take the image. Although if I moved back to the focused
area and pressed the shutter release it would beep and let me fire?
Is that right?

You have a camera that beeps?

If you are on focus priority, then you will need to use
the focus lock button if you move the focusing sensor
away from the target. If you are on release priority,
you will not. Except that if your target is in motion (or your
camera is--same effect) then the camera may in some
AF modes track the subject to a different sensor than
the original used for initial acquisition. Whether it does
depends on various settings and the relative size of the
target compared with the AF sensors and the gap between
them. You'll have to check after the fact to see whether
that happened, since it won't display while shooting but
will in the playback display (this only applies to the
dynamic AF modes).

Again, with the camera's AF in single servo mode (AF-S)
you get the focus lock (sometimes signalled with a beep)
when you get the focus, so you can recompose at will.
By default, AF-S is in focus priority. AF-C is normally not.
When it's in continuous servo mode, you either have to
leave it in either of the two release priority modes, or you
have to get used to using the AF-L button if you want to
recompose. Which one works best where depends on what
you're shooting. Focus priority can help for cutting down on
OOF shots, but you need to be able to use it with AF-C and
AF-ON by adding an AF-L rollover.

-- hide signature --

tom

Joseph S Wisniewski Forum Pro • Posts: 34,170
Calling fudgebrown!

You need to have a look at these two threads. Your "Picture: Shooting birds with canons (Nikon)" post has grown into a bloody flame war. They want your head in Norway.

http://forums.dpreview.com/forums/read.asp?forum=1021&message=22312573

http://forums.dpreview.com/forums/read.asp?forum=1021&message=22420702

-- hide signature --

Normally, a signature this small can't open its own jumpgate.

Ciao! Joe

http://www.swissarmyfork.com

 Joseph S Wisniewski's gear list:Joseph S Wisniewski's gear list
Canon EOS 5D Mark II Nikon D90 Nikon D2X Nikon D3 Nikon D100 +43 more
fudgebrown Senior Member • Posts: 2,640
Re: Calling fudgebrown!

that's because it's not my pic - i found it via digg.com (perhaps i should have stated it was not my pic).

Joseph S Wisniewski wrote:

You need to have a look at these two threads. Your "Picture:
Shooting birds with canons (Nikon)" post has grown into a bloody
flame war. They want your head in Norway.

http://forums.dpreview.com/forums/read.asp?forum=1021&message=22312573

http://forums.dpreview.com/forums/read.asp?forum=1021&message=22420702

-- hide signature --

'Procrastinate now, don't put it off.'

 fudgebrown's gear list:fudgebrown's gear list
Canon EOS 5D Mark III Nikon D810 Canon EF 50mm f/1.4 USM Canon EF 135mm F2L USM Canon EF 70-200mm f/2.8L USM +5 more
Kallel00 Senior Member • Posts: 1,043
Re: AF-ON how many use it and what are it's merits

Once you start using AF-ON there's no going back.

John Cote Senior Member • Posts: 1,480
It is really easier than all this.

fudgebrown wrote:

John, forgive me for not simply reading my own D200 manual but i
have a question -

does that mean the AF-ON button while held down is essentially
AF-C, and as soon as you let go it locks focus - then you can take
your shot?

I guess that all I meant is that if you take the focus control off of the shutter button and put is exclusively on the AF-ON button focus is essentially locked when you remove your thumb from the AF-ON button because there is no way for the camera to continue focusing. It will stay focused on what you left it focused on....because you are not telling it to focus anymore. This is what I mean by focus lock.

This does not mean that you are locked up and have to do something weird to start focusing again. All you have to do is put your thumb down on the button again and start focusing again.

Also, BTW, one of the best applications for this technique is for portraits and close up shots when using AFS lenses. I almost always manually focus close-up work, but by using the AF-ON button to achieve as close a focus as the camera will give me, I can either choose to use the camera's focus, or when it does what it invariably does and focuses on the eyebrows instead of the eyeball, I can manually tweak a little and get the perfect shot very quickly.

This technique ain't just for sports and birds.

-- hide signature --

John Cote
http://www.johncotephotography.com

'Cameras are just cr@p we have to lug around because there is no direct brain to printer connection...yet!'

 John Cote's gear list:John Cote's gear list
Nikon D4S Nikon D850 Nikon AF-S Nikkor 14-24mm f/2.8G ED Nikon AF-S Nikkor 24-70mm f/2.8G ED Nikon AF-S Nikkor 70-200mm f/2.8G ED VR II +4 more
fudgebrown Senior Member • Posts: 2,640
Re: It is really easier than all this.

thanks john, it works exactly as i understood it. I have never used the AF-ON button regularly, but i have discovered limitations to relying on the shutter for both focus and capture, therefore I will try the AF-ON solution. So far I love it, since I know I'll never miss a shot (that's more so because i changed the shutter to release rather than focus).

John Cote wrote:

fudgebrown wrote:

John, forgive me for not simply reading my own D200 manual but i
have a question -

does that mean the AF-ON button while held down is essentially
AF-C, and as soon as you let go it locks focus - then you can take
your shot?

I guess that all I meant is that if you take the focus control off
of the shutter button and put is exclusively on the AF-ON button
focus is essentially locked when you remove your thumb from the
AF-ON button because there is no way for the camera to continue
focusing. It will stay focused on what you left it focused
on....because you are not telling it to focus anymore. This is what
I mean by focus lock.

This does not mean that you are locked up and have to do something
weird to start focusing again. All you have to do is put your thumb
down on the button again and start focusing again.

Also, BTW, one of the best applications for this technique is for
portraits and close up shots when using AFS lenses. I almost always
manually focus close-up work, but by using the AF-ON button to
achieve as close a focus as the camera will give me, I can either
choose to use the camera's focus, or when it does what it
invariably does and focuses on the eyebrows instead of the eyeball,
I can manually tweak a little and get the perfect shot very quickly.

This technique ain't just for sports and birds.

-- hide signature --

'Procrastinate now, don't put it off.'

 fudgebrown's gear list:fudgebrown's gear list
Canon EOS 5D Mark III Nikon D810 Canon EF 50mm f/1.4 USM Canon EF 135mm F2L USM Canon EF 70-200mm f/2.8L USM +5 more
jeff-c Senior Member • Posts: 2,096
Custom Function Bank

Randy Z wrote:

I can focus/recompose only once for a series, and don't have to
keep the shutter button half-pressed.

Disadvantage: You can't hand the camera to a friend to take a shot
without re-enabling the shutter button focus.

This is where the custom function bank comes handy. On my D200 bank D is named as "Candid", probably should have it named "Wife". In that bank the camera AF function is reset to the factory default mode so when I hand my camera to someone else I always quickly change to this bank first.

 jeff-c's gear list:jeff-c's gear list
Nikon Coolpix 990 Sigma DP3 Merrill Nikon D50 Nikon D700 Olympus PEN E-P1 +26 more
Gabby498 Forum Member • Posts: 75
Re: AF-ON how many use it and what are it's merits

Builder, not to complicate things but there is more than one-way to do this. Using the AF-ON to lock and hold focus seems fine for sports or wildlife, but if that is not what you are shooting you may have a little more flexibility.

I have both AF-C and AF-S set to Focus Priority
I have the AF-ON set to Shutter/AF-ON (shows ON in the A menu)

This allows me the option, without going into a menu, to use either the shutter button or the AF-ON button for focusing. The difference is that to hold the focus I have to continue holding the AF-ON button down until I take the photograph. This works exceptionally well for me on shooting people pictures or portraits along with my general shooting.

I use the AF-L/AE-L set to lock and hold focus only and the Function Button to select spot metering.

I can use either matrix metering or, by pressing the Function Button, select an area to spot meter and press the AFL/AFE to lock and hold the exposure and release the button, select the area to focus, press and hold the AF-ON, compose and shoot. Or if matrix metering and half press will work for the situation, I can use that. All without taking my eye away from the viewfinder.

It's a little like playing a three keyed accordion but it does not take long to adjust to it. And it is doesn't really lock you into a particular way of using your camera.

winnie Veteran Member • Posts: 4,224
Thanks Tom & Thomas

My brain hurts now ;0). Mind blowing stuff at the moment but I am sure I will get it when I try it out in anger on a proper subject.

Cheers

Alex
--
------------------------------------------------
http://www.alexwinserphotography.co.uk

slimandy Forum Pro • Posts: 17,157
Re: AF-ON how many use it and what are it's merits

I use it. I also used it on my F100. I changed the setting for the exp lock on my D100 so I could use it on that too. I use it in conjunction with AF-C mode. It gives me total control. The camera will continue to focus while I push the button and will not try to re-focuss until I push it again.

 slimandy's gear list:slimandy's gear list
Sony RX100 II Nikon D200 Nikon D700 Fujifilm X-E1 Fujifilm X-T1
Builder Contributing Member • Posts: 921
Re: AF-ON how many use it and what are it's merits

Ouch - you made my brain hurt there

I only ever use the lock button for locking exposure, I've never tried to do anything with focus there, preferring to use the shutter (although AF-ON seems to rock after trying it last night).

The idea of setting the function button to do spot meter and then locking the exposure with that sounds very cool, but I'll have to play with it to find out how to use it right

TrekSF6 Veteran Member • Posts: 4,090
Re: AF-ON how many use it and what are it's merits

Absolutely love this button. I will never buy another DSLR without it. It is great in any situation.
focus, reframe and shoot without having to hold the shutter button halfway.

Using continuous servo focus and 5 fps, you can push the button when you want it to focus on a certain target, then let go until you want to push it again to focus on another target, while continuously shooting the whole time.
Soooo much better having the focus control independent of the shutter button.
--
Scott A.

 TrekSF6's gear list:TrekSF6's gear list
Sony a6500 Sony E 50mm F1.8 OSS Sony E 55-210mm F4.5-6.3 OSS Samyang 12mm F2.0 NCS CS Sony FE 28mm F2 +1 more
matthew saville
matthew saville Senior Member • Posts: 2,133
Can't imagine living without it...

Sometimes I can't hardly imagine NOT having auto focus dis-jointed from the shutter release. There's just no way I could shoot effectively if I had AF doing it's thing EVERY time I touch the shutter release. Focus is critical, and I want to be in complete control.

Having an AF-ON button, PLUS any AF-S (or HSM) lens, is an addiction. I effectively have complete, full-time antofocus at my disposal AND complete manual focus whenever I want it, without having to flip ANY switches or anything. If I want AF, I just hit the AF button. If I want MF, I just grabe the focus ring and focus. Perfect, seamless co-existence...

SOMEtimes in really active situations I want to be able to shoot one-handed, or I want to idiot-proof my camera, in which case I'll set the camera to AF via the shutter release. But those conditions are very few and far between.

Give AF-ON a try, I advise everyone. If you're not addicted after maybe a week or two of shooting, switch back. But I'm betting that you'll think to yourself, "how did I ever do without this?"

-- hide signature --
mosman Contributing Member • Posts: 877
Re: Custom Function Bank

jeff-c wrote:

This is where the custom function bank comes handy. On my D200 bank
D is named as "Candid", probably should have it named "Wife".

You are indeed a brave man

Mosman

 mosman's gear list:mosman's gear list
Nikon D3 Nikon D3X Nikon D800 Nikon D5200 Nikon Df +11 more
Ola Forsslund Regular Member • Posts: 451
I dont see why AF-on would help here

Nigel_L wrote:

You can pre-focus on the subject (using the AF-ON button) and then
press the shutter release as soon as you see the "special moment".

Sure, but you can do the same by half-pressing or using af-lock, I don't see the advantage here (?).

 Ola Forsslund's gear list:Ola Forsslund's gear list
Nikon D800 Nikon AF-S Nikkor 70-200mm f/2.8G ED VR Nikon AF Nikkor 20mm f/2.8D Nikon AF Nikkor 50mm f/1.8D Nikon AF-S Teleconverter TC-20E III
harlot Contributing Member • Posts: 938
Re: You be in control..not the camera

Hi John (and all),

I've read this thread a couple of times and I must admit I'm having trouble understanding the different ways of locking focus with the D200. I'm sorry if this questions sound silly, but the camera's manual doesn't help much with this.

There is something basic I don't understand. Are you saying in your post that if I press the shutter button halfway, the focus doesn't stay blocked until I press it all the way down? Are tou saying that when I press it all the way down the camera will change the oicus? I don't mean pressing it halfway and then recomposing. I mean pressing it halfway, not moving the camera and then pressing it all the way down.

There's something else I don't understand. Let's say that I want to block the focus with the AE button in order to recompose. If I focus, say, in the eye of a person, then press the AE button to block the focus and recompose to let in the frame a tree or another person that is at the left (out of the frame until that moment), the chances that the eye of the person in which I blocked the focus come out perfectly focused are minimal, right? So what's the use of the AE button? Or am I missing something here? (I know I'm missing a lot ).

Thanks,

Daniel

John Cote wrote:

michael wrote:

I would be interested on how many of you use this button and why ?
--
Michael
http://www.pbase.com/yube
http://www.shuttercity.com/ShowGallery.cfm?AcctID=1854

Michael,

If you use the shutter button, you need to press an AF lock button
or the camera will refocus when you take a photo. I want the camera
to be focused on what I focus it on. Not some high contrast area it
likes near what I want of a fence behind the subject.

Switching focus to the AF-ON button and off of the shutter button
means that after I take my finger off the AF-ON button, focus is
locked. When I take the picture the camera can not re-focus.

To me, focusing and taking are two different functions. I do not
want the to happen together with the press of a single button.

It takes a while to get used to this but once you do, you will
never switch back. It also allows you to manually tweak the focus
with AFS lenses and not have the camera refoucs back to where it
had mis-focused originally.

IT ALLOWS YOU TO BE IN CONTROL.

harlot Contributing Member • Posts: 938
Re: You be in control..not the camera

Sorry, I meant the AF lock (not AE 'block'). That's my poor English.

Daniel

pixelfixer Contributing Member • Posts: 714
Re: AF-ON how many use it and what are it's merits
Farhad Hayat Regular Member • Posts: 152
Re: AF-ON how many use it and what are it's merits

OK

cayzi Contributing Member • Posts: 558
Re: AF-ON

Tom Christiansen wrote:
If you are on focus priority, then you will need to use
the focus lock button

You mean AF/AE lock button set to AF-lock option?

Again, with the camera's AF in single servo mode (AF-S)
you get the focus lock (sometimes signalled with a beep)
when you get the focus, so you can recompose at will.

Usually when I have set to AF-S mode I do a focus on subject and then recompose to get a shoot. But that is only valid until subject is not moving.

By default, AF-S is in focus priority. AF-C is normally not.
When it's in continuous servo mode, you either have to
leave it in either of the two release priority modes, or you
have to get used to using the AF-L button if you want to
recompose.

Are you trying to say when I put camera in focus priority mode then Af-on will not work, so I have to use AF-lock button. Will camera follow the subject if it is moving or not in this case?

If I have a1 custom function set to release mode then Af-on will track the subject while I will have af-on pressed on. What happend if I use AF-lock in this case?

Which one works best where depends on what
you're shooting. Focus priority can help for cutting down on
OOF shots, but you need to be able to use it with AF-C and
AF-ON by adding an AF-L rollover.

That I want to know - I ask this question upper.

How does buttons like AF-lock and AF-on works in combination how AF-C (AF-S) priority selection (a1) is set?

Thanks for answers!!!

Keyboard shortcuts:
FForum MMy threads