D600 AF-on button

fred

Hi, 

I assigned the AEL button to AF-on and even though I assigned my autofocus to focus priority and not release my shutter still clicks even if the subject is out of focus. Does anyone have the same problem Im encountering?

jonnyapple

Fred, probably you've done this, but hold down your AF button to make sure you're not in AF-C mode. In AF-S it won't release the shutter unless focus is acquired, which is what it sounds like you want to do. Alternatively, you can adjust the AF-C priority selection flag (custom setting a1 on my D7000, presumably the same on the D600) to have focus priority selection for AF-C instead of release priority.

I had always wondered about why they had that custom setting to change, but I guess it does make sense in a setting where you want to do 3D focus tracking and only want the shutter to release when focus is acquired.

fred

Hi Jonny, I think you have it backwards. When I use the AF-C shutter will not fire until focus is acquired which is not the case with AF-S. Shutter snaps even if out of focus. I am not familiar with D7000 but I guess its the same with D600 so if you will please set your AEL to AF-on button and with your autofocus mode set to AF-S with focus priority, then focus on a subject using the AF-on button and once you acquire focus try moving your camera away to something not in focus and the shutter will still fire.. Tell me what happens.. thanks

PB_PM

I think there are separate settings for AF-S and AF-C, if the D600 is anything like the D7000/D300/D800 etc. Make sure the focus settings for AF-S are set properly.

fred

There are only two focus settings for AF-S on D600 which are release or focus priority. On focus priority shutter still fires even if subject is out of focus. It is not the case with my D90, I can not press shutter if subject is not focus on AF-S..

jonnyapple

Rob said what I thought. The a1 and a2 custom flags are priority selectors for AF-C and AF-S, respectively. The defaults are shutter priority and focus priority, respectively. I don't think they would change the ability to set this for each mode independently, so if it's not working as I described above I would call that a firmware bug. I tried on my D7000 and it works like I said.

Just for kicks, try setting both a1 and a2 to focus priority and see if anything changes.

jonnyapple

One more thing. When I said press the AF button above, I mean the one to the left of your lens, not the one you assigned to AF-ON. Does holding that button make AF-S or AF-C show in the viewfinder and/or LCD?

Edit: C stands for continuous, S stands for single, referring to focus acquisition. I don't think what I said was backwards.

Parke1953

If you focus on a subject with the AF-on and keep it depressed (you have locked the focus) and then recompose on a subject at a different distance it will fire because you still have acquired focus on the subject. Maybe i don't understand what you are saying.

Parke1953

Reread the thread and i think I understand now.
Wow Fred you are right. If I set a4 AF activation to AF-on only and a2 AF-S priority selection to focus it will fire even if it is not in focus. Should it do that? This is on a D800.

fred

Yes that is exactly m point. It doesnt do that on my D90. When pressing AF-ON and subject is in focus you can trigger the shutter however while still pressing the AF-on button and you recompose it triggers the shutter even if its out of focus. It doesnt do that on my D90, you cant trigger the shutter if its out of focus. 

jonnyapple

Is this true even if you release the AE-L/AF-L button or are you recomposing while the button is down? That's completely the wrong behavior and I just checked again that it doesn't work as you're describing on the D7000. I think you should let Nikon know about that.

fred

I think its a bug that nikon should address by releasing a firmware update for D600 and if you said yours is D800 so they should also release one for that model.

jonnyapple

Oh, if I recompose holding down AF-ON, I can still release the shutter. 

fred

even if its out of focus right? That is not the case with my D90 and thats why Im bothered with this since its a newer model than the D90..

jonnyapple

Yes, even if the recomposed area is out of focus. This is actually how I'd expect it to work, but I don't use AF-ON (maybe I should switch).

fred

switch to what? canon? hehehe

jonnyapple

If they're the only ones who make the AF-ON button work right, then maybe. ;-)

fred

I think nikon should release a firmware to address this since the focus priority is useless if you can trigger the shutter when a subject is out of focus which clearly contradicts what they are saying in page 97 of D600 manual.. I dont know what page explains the autofocus in D7000 manual 

Parke1953

Somehow I remember this was brought up in the old forum before I had the D800 (I think). Maybe I don't remember. Dang it's hell getting old.

fred

Hi Parke whats the use of Focus priority if you can trigger the shutter when subject is out of focus right? Might as well use the Release priority if thats the case...

Parke1953

Your right makes no difference if you use focus or release priority.
I'm going to think about it. See what I come up with. It looks like if you use the AF-on only then you focus on your subject then remove your finger from the AF-on your focus is locked and if you recompose subject distance is still in focus, however if subject moves then you need to refocus. But that doesn't answer why it will fire when not in focus. I'm tired my mom has been sick for the last 6 weeks or so. I'll think tomorrow maybe.

friedmud

Fred,

Maybe I'm missing something, but it sounds to me like it's working exactly as intended.

When in AF-S mode with focus priority the AF system will obtain a "lock" on a subject before the shutter can fire. That "lock" just sets the focus distance and in AF-S mode that distance will be maintained until you let off AF-on and press it again (at which point it will try to lock on a new subject).

However, after obtaining that lock you are free to move the camera to "recompose". Yes, that does mean that you can move the camera in a way that renders your intended subject out of focus. As long as the AF has been locked (and that lock is being maintained by holding down AF-on or holding the shutter halfway down when not using AF-on) the camera does not care.... It will let you do what you want and will happily fire the shutter when you press it. It believes that you are doing what you intend.

All of this is necessary to be able to focus and recompose. If you are not familiar with the "focus and recompose" technique here is a good primer: http://photographylife.com/focus-and-recompose-technique

The "focus priority" setting for AF-S only means that the shutter won't fire until that initial lock is made. To test this, go into a dark room and point your camera at a bland wall and press AF-on and immediately press the shutter button and hold it. While the camera hunts for a focus lock the shutter won't fire, but as soon as it obtains a lock (if it does) the shutter will then fire.

If you were in "release priority" in AF-S mode and did the above test the shutter would fire immediately when you press the shutter button... regardless of if a lock has been made.

Think of AF-S mode like this: the camera is only going to focus ONCE (that S is for Single) and obtain a "lock" after that the camera is never again going to even query the focus points. This gives you the freedom to recompose the shot.

In AF-C that's not the case, the camera is constantly querying the focus points... and with focus priority a subject must be under a focus point and in focus for the shutter to fire. You CANNOT do "focus and recompose" in AF-C because of this unless you are using AF-on or AE/AFL (again, see the link above).

Hopefully this helps.

Friedmud

Graystar

I agree that this is working correctly.  My D90 behaves the same way.  In AF-S, if I press the AE-L (set to AF-ON) and keep it pressed, then the focus lock remains and the shutter releases regardless of whether the scene is in focus or not.

That's basically what it means to have a focus lock, and why the AF-ON method of "focus lock" (letting go go of the AF-ON button) isn't really a focus lock.  That's one reason why AF-ON users keep the camera on AF-C (but then you get no AF-Assist from the camera or speedlights in low light, and you always need to be sure that your focus has been achieved before releasing the shutter.)

Msmoto

@ ;friedmud

+1  or..as one might put it...enough said.